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How to build a 50k ton forging press

hwillis
38 replies
1d1h

Forgings have the added advantage of variable grain direction which generally can be tailored to the stress patterns of a specific design.

This is a super underappreciated fact! It's often repeated that forging is just stronger, but just squishing steel does NOT make it stronger. Forging a part is so much more than just smashing it into a shape.

Steel cable is made of pretty ordinary steel which is stretched 100s of times its original length. That process alone makes it 2-4x stronger in that direction. You stretch steel and it gets stronger in that direction.

Do you see how complicated that optimization process becomes? The process steps are not just trying to take it to the final shape. Your piston rod needs to be strong lengthwise, so you actually want to start with a short fat ingot and stretch it out instead of one that is near-final size.

Think of making an I-beam. You could hammer out the middle, making it thinner. That would give you a bit of strength there but very little on the edges. If you instead pull the edges out, you create a long continuous stretch that will be very strong against bending. Where, how, and in what order you stretch makes all the difference. You may want to leave extra material and cut it off later, so that your grains are all oriented together instead of tapering to a point.

For any moderately complex part, this process is as complicated as modern engineering problems. With poor steel you genuinely need to understand how to foster and bring out those continuous lines or your corkscrew will unwind like playdough. Blacksmiths had a legitimately intellectual job back in the day!

HPsquared
12 replies
1d1h

This effect also applies to polymers! Perhaps even more so. Take a polyethylene bag (LDPE) and stretch the material in one direction. You might notice the material becomes thinner but also stronger. This is due to the polymer chains becoming aligned. Eventually you get "drawn fibers" where the molecular strands are aligned with the fibers for optimum tensile strength.

wizardforhire
8 replies
18h34m

This is exactly what dyneema is only with hdpe.

kragen
7 replies
14h57m

no, dyneema is not hdpe; it's uhmwpe, and it isn't just strain-hardened, it's gelspun

libria
5 replies
13h19m

Assuming these terms are all correctly spelled, this has to be the shortest sentence I've understood the least of on HN.

Guess I've got some googling to do.

NavinF
3 replies
12h23m

UHMW = ultra high molecular weight. Each molecule is literally heavy because they have a lot of atoms.

PE = polyethylene. The most popular plastic on this planet.

HDPE = high-density polyethylene. One of the most common plastics. Milk jugs, glue bottles, etc.

Stick some UHMW tape on anything that needs to slide easier. Its surface is quite slippery

jessebro
2 replies
5h11m

HDPE is also what Nalgenes and the like are made of (or used to be anyway), and is very popular for storing chemicals as well. It is very nearly completely inert.

kragen
1 replies
3h53m

you cunninghammed me: nalgenes are polycarbonate, which is a lot less inert

all the polyethylenes are relatively inert, because polyethylenes are in some sense just heavy paraffins. paraffin is germanized latin for 'relatively inert'

PuffinBlue
0 replies
1h45m

And you have Cunninghammed me :-)

Some Nalgene's are polycarbonate, like those commonly drunk from. But not all, some are HDPE[0,1,2].

Some are Polypropylene co-polymer[3] but those are more for specialist things I guess.

[0] https://ultralightoutdoorgear.co.uk/ultralite-1-litre-wide-m... [1] https://www.cotswoldoutdoor.com/p/nalgene-hdpe-125ml-wide-mo... [2] https://www.elitemountainsupplies.co.uk/camping-trekking-c4/... [3] https://www.thelabwarehouse.com/products/bottle-nalgene-ppco...

kragen
0 replies
12h55m

they are! sorry to be telegraphic

wizardforhire
0 replies
8h51m

I stand corrected! Thanks for the headsup <3s

01HNNWZ0MV43FF
1 replies
1d

That makes sense, if I don't rip open a bag on the first try it'll just stretch and never open

myself248
0 replies
17h41m

Stretch it in one direction, then grab in the middle of the stretched area and pull sideways, and it pops open like nothing.

kragen
0 replies
21h24m

it varies a lot with polymers, and it's a different effect. steel is entirely crystalline; ldpe is mostly amorphous. a big part of what's happening in the strain hardening of ldpe, aside from making it uniaxially oriented, is that it's crystallizing; the crystalline domains become larger, greatly reducing the amorphous volume fraction. (there are also other ways of achieving this effect, such as annealing, which you will notice softens steel rather than hardening it.) ldpe's strength isn't determined by crystal dislocation density in the same way as steel's, and of course steel doesn't have polymer chains to align

thaumasiotes
7 replies
1d1h

Blacksmiths had a legitimately intellectual job back in the day!

ACOUP noted that blacksmiths might be assisted by unskilled laborers, strikers, who had the actual job of lifting the hammer and hitting the object with it.

NegativeLatency
6 replies
1d

Unskilled feels unfair, it requires a fair bit of skill, and you're also learning how to forge while doing it.

droopyEyelids
2 replies
1d

This has been such a frustrating culture war definitional argument.

knodi123
1 replies
23h29m

Not necessarily a culture war thing. People who aren't familiar with the subject might take "unskilled" in the plain-english sense, as a pejorative. And who can blame them? We're english speakers before we're technical speakers.

Make gracious assumptions.

jessebro
0 replies
5h8m

Anyone who has worked in a job classified 'unskilled' generally doesn't need a pejorative to feel unloved. It's the nature of the game.

Digging ditches generally sucks, same as I imagine being a striker, but most anyone can do it (until their body gives out, anyway, which in some cases is 'immediately').

thaumasiotes
0 replies
20h31m

Unskilled feels unfair, it requires a fair bit of skill, and you're also learning how to forge while doing it.

Both of those points are untrue. Strikers are unskilled labor and in general are not learning how to forge. The smith shows where he wants the hammer to fall, and they let it fall there.

https://acoup.blog/2020/10/02/collections-iron-how-did-they-...

Things were worse for the many strikers and other laborers who were essentially unskilled hired hands or even enslaved laborers (given their depiction in artwork, it seems likely many ancient strikers were slaves) of much lower status and who could not expect to be trained into blacksmiths themselves some day. While some strikers were probably apprentices in training, it is quite clear that not all of them were! These workers would also have been far less richly paid; indeed, the entire point of strikers was to have laborers who could be paid very little but still amplify the production ability of the blacksmith himself.

(emphasis original)

bell-cot
0 replies
21h20m

The reality is that, depending on circumstances, a highly skilled craftsman of yesteryear could have any number of obviously less-skilled assistants. Some would be "career track", some semi-skilled seasonal help, some minimally-skilled (whether due to youth, infrequent day labor, poor talent, or social status), and some in supporting type of skilled work - animal handling, cooking, bookkeeping, etc.

Terr_
0 replies
20h42m

I tried to maintain a certain kind of optimistic humility, that almost anything which employs a person full-time is a problem-area that has fractal layers of complexity one don't have to know from the outside.

The only question is whether someone will pay you for doing the fancy skill/science tricks or not.

abe_m
7 replies
18h44m

I'd really like to see some backing of these claims. I've seen "grain flow" claiming big gains for years in various enthusiast magazines (bike, motorcycles, cars, etc) as to why components are forged.

Then I started working in engineering, and I can't find any support for these claims. For sure when a steel bar is worked down to become wire for a steel rope, it cannot be pulled to an elongation of 100x increasing strength. A36 steel which is a basic structural steel has an elongation at break of 23% in a 2" gauge length [1]. In every rolling mill I've been in, there is a limited amount of reduction per pass through the mill, after which the metal needs to go for thermal treatment to be annealed to remove all the cold work. Every time you anneal the material, you completely resets the elongation (internal plastic strain) and strengthening due to work hardening. If they do too much reduction in one pass or at too low of a temperature, it cracks the material and makes it weaker.

For sheet metal, there is lore about the material being stronger in the rolling direction as that is the direction of grain flow. I have yet to find a source that can point to any large difference. In papers like this [2] there are claims of certain orientations of samples relative to rolling direction have different tensile properties, but when you look at the tensile charts, there is minimal difference. The yield strength in these charts isn't reported, but all three orientations look to yield at the same point. In this test the across the grain (90 degree to rolling direction) orientation had the highest tensile strength which is the opposite of the expectation of the forging "grain flow" promoters. But the magnitude of the difference isn't large, and is small relative to normal factors of safety in a reasonable design.

When designing automotive components, I've only ever seen forging methods selected for efficiency of production. If a part mostly fills the envelope of a bar or plate, it is cut from bar or plate in all cases. If there is a lot of void volume in the part, the calculation will be made to determine if the cost of developing forging tooling and development will get paid back in reduced material and machining cost. I have yet to see the dimensions of the part change with manufacturing method, which would be needed if the non-forged part was significantly weaker.

And finally, a lot of forged parts are subsequently heat treated. When heat treating steel all of the grains in the steel have to be destroyed and recrystallized. That is the mechanism by which heat treatment works. Depending on the exact process and part geometry, this process removes or reduces the grain flow in the finished parts.

Having said that, the claim of superiority of forging persists, and I'd love to see a technical reference that shows the magnitude of the change from someone who has plausibly actually tested the effect.

[1] https://matweb.com/search/DataSheet.aspx?MatGUID=d1844977c5c... [2] https://www.researchgate.net/publication/283447700_The_effec...

bobeboph
2 replies
12h19m

MIL-HDBK-5 [1] is a good publically-available source for strength allowables for several aerospace alloys, including multiple directions relative to the grain for some of them.

The first relevant example I found was on page 3-86, extruded 2024, 2.250 - 2.499 inch cross-section. For ultimate tensile strength, F_tu, the L (in the direction of extrusion) allowable is 57 ksi, while the LT (perpendicular to the direction of extrusion) allowable is 39 ksi. That's a 30% drop in strength.

[1] http://everyspec.com/MIL-HDBK/MIL-HDBK-0001-0099/MIL_HDBK_5J...

kragen
0 replies
3h36m

this is a fantastic find, thanks!

buildsjets
0 replies
2h14m

Thanks for posting that as I was about to! I will note that MIL-HDBK-5 is no longer valid for actual aerospace design, as it has been superseded by Battelle Institute's MMPDS Handbook, which is locked behind a very very tall paywall. The MIL-HDBK is still all perfectly good data.

https://www.mmpds.org/

azalemeth
1 replies
6h43m

The best evidence for grain flow on a really atomic scale comes from what is called texture analysis in X-ray or electron-beam crystallography (or related techniques): you get a deviation in the distribution of Bragg peaks due to the fact that you have a non uniform distribution over the orientation of the unit cells within the crystallites in the bulk material. You can fit this in a spherical harmonic basis and quite accurately work out the excess or defect of the distribution, typically quantified in units of 'multiple of a random distribution' or mrd, again either in crystallographic axes or traditionally in three orthonormal axes – parallel to the surface of the workpiece ("rolling direction"), axially transverse to it, and normal to it. The phrase to search for is 'pole plot'. They're rotationally symmetric and an inverse projection over all space, and so usually only a quarter of a hemisphere is shown.

A very good example of the affect of annealing tungsten wire is here [1] – note that (a) there is a very clear orientation dependence that some difficult geometric transformations will undoubtedly show means that they are aligned in the wire drawing dimension; and (b) after annealing at 1600 ºC for an hour the preference is slightly reduced but still about 15 sigma away from random...

[1] https://www.researchgate.net/figure/001-110-and-111-pole-fig...

kragen
0 replies
3h37m

but 1600° for tungsten is still barely above its ductile-to-brittle transition, isn't it? because that can be up to 967°

kragen
0 replies
14h32m

your comment is an extremely valuable contribution!

disclaimer: i don't have a relevant technical reference handy, and i'm far from an expert on the area, which is vast, and i recognize you know things i don't about it. still, i do spend a lot of time reading papers with metallurgical micrographs in them†, and i think i figured out the answer to your question many years ago, so i will explain my understanding

except for the part about grain orientation, anyway

In every rolling mill I've been in, there is a limited amount of reduction per pass through the mill, after which the metal needs to go for thermal treatment to be annealed to remove all the cold work. Every time you anneal the material, you completely resets the elongation (internal plastic strain) and strengthening due to work hardening. If they do too much reduction in one pass or at too low of a temperature, it cracks the material and makes it weaker.

as i understand it, this is exactly right, but you say it as if it's contradictory. strain hardening increases the yield strength of metal (by making it yield). it can also change the tensile strength, but to a much smaller degree. when the metal can no longer handle stress by yielding, in particular by yielding in a way that produces further work hardening, so that the yield is distributed over the metal rather than being concentrated wherever it starts, it cracks. that's why strain hardening metal makes it more prone to cracking. in general, a given metal is more prone to cracking when you harden it, whether you harden it by cold forging, case hardening, or quenching. (peening is the exception; it inhibits crack initiation by a different method.)

https://en.wikipedia.org/wiki/Work_hardening has an overview that talks about how this phenomenon can be either desirable or undesirable

the change in yield strength from cold working can be quite large, a factor of 4 or so. it doesn't change the ultimate tensile strength much (or at all in the case of your wire rope), but there are a lot of cases where what you care about is the yield strength, not the uts, because if the part yields by more than a tiny amount, it is out of tolerance and has therefore failed

(with respect to a36 steel, elongation at break, and wire rope, this is a minor detail, but it's possible to elongate it somewhat more through rolling than you can through wire-drawing. but you are certainly correct that you cannot elongate it 100×, and wire rope is mostly made by drawing, not by rolling.)

there are different kinds of heat treatment, but the most common kind for steel involves a phase transition to austenite and back, which does indeed destroy the entire grain structure of the steel, losing any potential advantage of forging, precisely as you say. i'd think this would also be mostly true for hot-forging, where steel is forged while still austenitic; the relevant grain structure for strength will be the one that the steel acquires when it leaves the austenite phase. there are other kinds of heat treatment (more commonly used with things like aluminum) that don't involve fully recrystallizing the metal, and i would expect some grain structure to survive those

probably none of that is telling you anything you don't already know, but perhaps it's a different way of thinking about the things you know that explains the apparent contradictions

as for which direction i would expect grain orientation to make things strongest in, i really have no idea at all

______

† last night, for example, i read https://www.mdpi.com/2075-4701/8/2/91/pdf and https://www.jstage.jst.go.jp/article/jjspm/63/7/63_15-00089/..., but also parts of https://pure.tue.nl/ws/portalfiles/portal/1584410/617544.pdf, http://www.diva-portal.se/smash/get/diva2:1352113/FULLTEXT01..., https://yadda.icm.edu.pl/baztech/element/bwmeta1.element.baz..., https://www.imerys.com/public/2022-03/Specialty-Carbons-for-..., and https://backend.orbit.dtu.dk/ws/portalfiles/portal/200743982..., but i was maybe on a bit of an atypical metallurgy bender. none of these are more than marginally relevant to the questions at hand of forging, strain-hardening/work-hardening, and grain structure orientation

hwillis
0 replies
15h19m

It's plenty real, and it matters for more than just strength. Cold rolled grain oriented electrical steel has better magnetic properties than non-oriented steel and is used in some applications where the field is in a straight line.

pfdietz
3 replies
1d

I wonder if it's possible to do additive manufacturing with pre-elongated snippets of wire.

hwillis
2 replies
15h44m

annealing, which resets the grain structure, happens at a lower temperature than melting or sintering.

pfdietz
0 replies
7h36m

Doesn't annealing take hours, particularly at the lower range of temperatures? Perhaps the additive process can keep the metal hot for a much shorter time. Granted, this also means stresses from the manufacturing process will not be removed.

kragen
0 replies
14h55m

true, conventional welding or sintering would be a bad idea. but you can connect them together with brazing, laser-welding, explosive welding, ultrasonic welding, self-propagating high-temperature synthesis of an intermetallic like nickel aluminide, electrodeposition, lashing, or globs of glue

samstave
2 replies
20h56m

I have had this question in my mind for decades:

"Can you forge metals in a highly controlled and directed magnetic field where you can orient the grain/alignment of atoms/fields in whatever direction you want. Further, if true, what happens when you make damascus from varying plated that have particular alignments/grains - and what are the features of this material?
hwillis
1 replies
15h34m

Can you forge metals in a highly controlled and directed magnetic field where you can orient the grain/alignment of atoms/fields in whatever direction you want.

This is how you make magnets. "Soft" ferromagnets have small, round grains that rotate to reinforce outside fields. "Hard" ferromagnets have permanent fields of their own and long grains that can't reorient.

Forging with a field has a very low impact on the material properties because of how weak a magnetic field is compared to the forces moving atoms- same reason steel loses its magnetic properties when it gets hot.

what happens when you make damascus from varying plated that have particular alignments/grains

"Damascene" is the layered look most often made from acid etching sandwiched and forge-welded layers of different steels. Damascus is a single alloy for which the pattern is named.

Since in both cases the material is melted together, it's far too hot for any magnetic properties to have any impact.

samstave
0 replies
15h17m

Thanks for that.

Though I was thinking of super intense magnetic fields (like in CERN), however, Ill leave it to my Comic Book Science collection, then :-)

kragen
0 replies
21h55m

just squishing steel does NOT make it stronger

just squishing steel does actually make it stronger, because it increases the number of dislocations in its crystal structure. smaller grains mean higher strength even without the variable grain direction. also, peening, which is not exactly the same as forging but is also just squishing steel, can give you higher strength for a third reason: areas with residual compressive stress can't initiate cracks until you overcome that stress, which increases strength. even more, though, it increases fatigue resistance

tra3
25 replies
1d2h

Super interesting:

The largest, the 50,000-ton forging presses, were behemoths: each was the size of a ten-story building, and could exert enough force to lift an entire battleship. The 35,000-ton forging presses weren’t much smaller.

and then

Following Germany’s surrender, the U.S. and the Soviet Union divided up its large press capabilities as well as its rocket scientists. The U.S. dismantled four German presses and had them shipped back to the states

I wonder what the logistics for moving something like that across the ocean was. I know Soviets dismantled a bunch of factories during the war and moved them far behind the front lines...wonder what that was like.

hinkley
23 replies
1d

Well when you have military supply vessels just hanging around in the area…

tra3
22 replies
1d

For context, I work on my car a bit, and the shop manual for it is hundreds of pages (thousands?). Now scale it up to a factory, maybe without manuals. Disassemble, crate it, assemble it 5000 miles away.

Based on my software experience, I can sort of go in blind and figure out how a system functions. I suppose that translates to real world too..

hinkley
21 replies
1d

There’s a UX school that says that if the user needs the manual you fucked up. I mostly subscribe to that school. Mostly.

It drives my family nuts that I will assemble a piece of furniture without reading the instructions. But the thing is with a little mechanical sympathy, and a well designed product, there’s only one sensible way for the parts to go together, and if you organize them right while you disassemble it (granted, harder to do when shipping overseas) then you’re good.

Imagine you had a device where four hardened steel bolts held the critical parts together. It would be stupid if the handles used the same bolt sizes in mild steel, right? Someone will fuck that up and use the wrong spare parts or do deep maintenance wrong. You’d use a different size bolt so they can’t get mixed up.

WheatMillington
16 replies
21h36m

Your viewpoint is rather naive in the mechanical world. OK it's enough to assemble a coffee table, now try an engine with 2,000 parts. Without a manual how can you set bearing clearances? How do you know how much thrust clearance there should be? How do you know which way up a piston ring goes, or how much torque to apply to a head bolt?

Machines are extremely complex, and that's before you even touch electronics and hydraulics, both of which are highly complex systems. Simply moving large machine parts safely requires documented procedures, let alone order of assembly.

kragen
9 replies
21h20m

there's a lot of shade-tree mechanics who have successfully rebuilt engines with thousands of parts. essentially figuring out how to rebuild an engine is similar to figuring out how to build one from scratch, which is within human capacity, particularly with background knowledge. but the guy rebuilding the engine has a lot of hints

granted, he'll probably fuck up his first two or three pretty good without haynes or chilton

bacon_waffle
3 replies
16h12m

I've rebuilt several motors, transmissions, various other mechanical contrivances. Sometimes with decent documentation, sometimes not so much. Also done a bit of amateur machining, and worked as an engineer on physical products.

Under no circumstances would I claim that rebuilding a motor was essentially figuring out how to build one from scratch. In software, maybe that's like claiming that figuring out how to configure a new Linux box is essentially the same thing as figuring out how to write an OS.

kragen
2 replies
15h9m

yes, i agree. what i was trying to express is that rebuilding a motor is generally strictly easier than building one from scratch, because it's building a motor from something more than scratch. i don't think i expressed it very well

(i mean, if all the parts of your engine are trashed, you are going to have to machine replacements for them, and that might actually take you longer. but it's clearly achievable given that people have built internal combustion engines without a working example to take measurements from)

bacon_waffle
1 replies
14h18m

Ah, that helps, thanks.

It's a bit academic, but set theory doesn't really apply to such fuzzy human things as knowledge and experience. Repairing and designing are different pursuits which might have a lot of similarities, but I wouldn't presume that a design engineer could competently do the work of a technician.

Just consider that any particular field of engineering as might be described by a lay person, can be far too broad and deep for an individual to be competent in all facets of it. I'm reminded of my neighbour asking for some help configuring email for her new iPhone, because she knows I do computer work. Mainly firmware.

kragen
0 replies
14h9m

there's something to that, for sure; there are plenty of design engineers who don't know nearly as much as they think they do, and who depend heavily on the expertise of their technicians to get anything done in the real world. they could never build an engine on their own! but there are also others who are eminently capable at the technical level, and i think their designs benefit from that

repair and design have in common that they require a lot of hard thought about the causal relationships involved in making the artifact work, tracing the causal chains through until they break, then patching them up. but they both also certainly involve other skills that the other does not; design also requires figuring out how to make new things happen, which involves imagining things that have never happened, while repair also requires knowing how not to bust your knuckles or spill the gasoline

hinkley
2 replies
20h37m

There is a lot of stuff you can do when it’s pass fail. As a pro you have a time limit and you’re bad if you can’t rebuild in X hours.

My dad will tell you I helped him rebuild a bike coaster brake at 14. But the truth is the only decision he made was to buy the repair kit. I got rags and laid all the parts out like an exploded diagram, we cleaned them or swapped them and they went back in the way they came out.

I worked as a bike mechanic for two summers in college. Cars have manuals and maybe the mechanic you work for has them. Bicycles do not. You’re all shade-tree until you’ve seen everything a couple times.

kragen
1 replies
19h36m

yeah. thank god for sheldon brown

hinkley
0 replies
16h47m

I was more of a Brandt boy myself.

rlonstein
1 replies
18h54m

granted, he'll probably fuck up his first two or three pretty good without haynes or chilton

Given the assumptions, inaccuracies, and mistakes I've seen in some Haynes and Chilton manuals they'll probably fuck up with them. Factory manuals are usually worth the price (Honda's are, KTM's not so much).

kragen
0 replies
18h2m

i certainly did. haynes is no substitute for clue

hinkley
5 replies
20h34m

Does every car mechanic have the entire Chilton’s catalog or do the mechanics just have to memorize things or look them up on the Internet? My understanding is it used to be a little A and a lot of B, and now it’s a mix of B and C

WheatMillington
3 replies
20h28m

I was using the engine example as an analogy in an apparently failed attempt to help you appreciate the complexity involved. Mechanics in general will feel their way around an issue, but almost universally have access to paid repair databases when non-intuitive and complex issues come about.

hinkley
2 replies
16h46m

You might recall that we're all talking about manufacturing equipment that was exfiltrated as war reparations.

I'm much less convinced than you are about the availability of accurate and detailed manuals. Which is why I keep steering the conversation to more murky engineering projects.

But I do want to circle back to say that I did at some point higher up gloss over the importance of things like torque and clearances. I'm not trying to say that those are things you can just intuit. Even if we could both probably dig up an old mechanic who tightens things by feel.

krisoft
1 replies
6h19m

I don't understand the problem. You take the equipment, the manual, the guy who used to read the manual and maintain the equipment and the guy who wrote the manual and designed the equipment.

jessebro
0 replies
5h3m

Did we mention that the manual was burned, and the guy and the guy who wrote the manual died in the explosion that burned the manual?

It was at the end of a massively destructive war of annihilation.

tra3
0 replies
20h0m

I think everyone has access to full shop manuals in soft copy these days. I imagine it's a lot like writing code. You remember how to write a for loop (oil change? a brakes?) but have to look up API docs for more esoteric functions (a clutch job?).

FWIW here are Nissan factory manuals in all their glory: https://www.nicoclub.com/nissan-service-manuals

sushid
1 replies
21h7m

Sure, but now you have another bolt and nut configuration that requires a different drill, maybe a new supplier, etc. RTFM!

hinkley
0 replies
20h36m

Bolts and nuts in two different materials/grades are still two separate pieces of inventory to manage.

metadat
0 replies
14h21m

Sometimes the intuitive way is wrong and you end up damaging the piece.. ask me how I know.

jessebro
0 replies
5h4m

Better hope they done have one set of 50mm bolts which are mild steel, and another set that are hardened high tensive steel that aren't clearly marked and the same length!

Or you're going to have quite an adventure when you go to do your thing and a random selection of bolt heads come pinging off at you at mach 5.

bee_rider
19 replies
1d2h

They talk about machining, casting, and pressing. Mostly with casting and pressing in a good light, machining not so good.

As somebody who knows absolutely nothing about this stuff, I wonder—casting, I thought, was generally a lower quality option (like cast iron doesn’t have fantastic high-performance material qualities, and I had some crappy cast pewter toys as a kid). Are there different, higher quality casting processes, and I’ve only seen the bargain bin results? Is there a general ranking of the quality of the result or is it all very complicated and material specific?

spenczar5
5 replies
1d1h

Castings can achieve shapes that are impractical to machine. A classic example is a spoked wheel. The spokes are really hard to make precisely with machining, but fairly straightforward when casting. Bandsaw wheels are virtually always cast, for example.

Also, the processes are not really independent. It can be much cheaper to do a rough casting, and then machine just the critical faces of it, instead of using an “off the shelf” hunk of metal and machining it all into shape. So it’s not really “casting is superior to machining” or vice versa. More that machining is high precision but expensive. Casting has some up-front cost but once the patterns are made, each item will use material quite efficiently.

IshKebab
4 replies
1d1h

Spoked wheels aren't cast because it's hard to machine them. You can easily CNC them if you really want. But that would be insanely expensive and wasteful and not any better.

spenczar5
2 replies
1d1h

Yes, I said “impractical”, not “impossible”.

IshKebab
1 replies
22h12m

You said

The spokes are really hard to make precisely with machining

That is not true.

jessebro
0 replies
4h54m

Back in the days of manual machining it was definitely true. CNC, especially modern 5+ axis high speed high rigidity machines are god level cheating.

buildsjets
0 replies
21h50m

I've watched enough Chip Foose on TV to know that in the custom car world it is commonplace to start with a solid blank wheel and CNC away 90% of the face to achieve any particular design. It takes only minutes, and unlike casting or forging you do not need to purchase hard tooling for each different design.

https://www.youtube.com/watch?v=nqOlM6-YIIs

hwillis
3 replies
1d2h

like cast iron doesn’t have fantastic high-performance material qualities

Cast iron is a material, not a process. It's an unfortunate legacy term for very high carbon steel (>2% by weight, or <11 iron atoms per carbon atom). For reference "standard" steel is ~.08-.18% carbon, and high-carbon steel is ~.8% carbon.

The >1% carbon precipitates out into graphite within the steel, causing it to behave totally differently. Less rusting, but weaker and much more brittle when solid. Less viscous when liquid, so you can cast long and thin parts.

Are there different, higher quality casting processes, and I’ve only seen the bargain bin results?

There are, but it mostly is independent of the material. Some turbine blades are cast as single crystals for heat stability; you can't really cut a single crystal without introducing cracks and issues. There's also vacuum casting and spin casting (using a centrifuge to force liquid into the mold), which lets you cast metals that react with air or cool too quickly for normal methods.

Most of the variation in process is about the final form you cast into, though. Engine blocks are sometimes cast into a one-off ceramic shell that is sprayed onto a sand form. It's an expensive process but it lets you do the whole thing in one step.

is it all very complicated and material specific?

It is very material specific. Fundamentally its all about shaping the grains. In many steels you can physically alter grains. In others, like precipitation grains (aluminum alloys, some steels) the structure is determined by the cooling and you can't physically shape them. In that case you may often get a better structure by casting since you can choose how to cool parts down, while a billet will have a homogenous structure that is usually worse towards the center.

hedgehog
1 replies
1d1h

Monocrystalline turbine blades are one of those things that make me appreciate how deep the state of the art is for a lot of "simple" things when you look closely.

eternauta3k
0 replies
6h29m

There's nothing simple about jet engines :)

pfdietz
0 replies
1d

The >1% carbon precipitates out into graphite within the steel, causing it to behave totally differently. Less rusting, but weaker and much more brittle when solid.

If one adds some magnesium or cerium to the alloy, the graphite precipitates out as spherical nodules rather than feathery dendrites. The resulting material, called ductile iron, is much less brittle than traditional cast iron.

An advantage of the higher carbon content is a reduction in the melting point (by > 300 C), so the material is easier to cast than low carbon steel.

debacle
2 replies
1d2h

Casting isn't necessarily "lower quality," it just has different properties. It's also much older (by thousands of years) than machining or pressing, but you can't get to the pressing or machining step without having an ingot, which comes from the casting process.

The main drawbacks of casting are you get a hard, but brittle product with (generally) uneven quality. There are processes (like annealing, though I don't know how you anneal a massive component) that can solve these problems, but all iron/steel is "cast" at some point.

kragen
0 replies
19h39m

depends on what you mean by 'machining'. grinding is at least 7000 years old https://en.wikipedia.org/wiki/Shoe-last_celt and roughly contemporary with pottery. casting presumably began with pottery but was definitely in full swing by the bronze age, a mere few thousand years later

BlueTemplar
0 replies
1d

Until the mid-1800s, basically only the Chinese used cast iron, since it's so brittle. Ingots would come from smelting, not casting.

bluGill
1 replies
1d

Which cast iron? There are many different grades/alloys with different properties. Sometimes cast iron (some specific grade) is better sometimes it is worse. And of course you can cast things other than iron, cast steel does exist (rare outside the feed to a press, roll, or some other process, but you can cast steel into a specific shape if you want to). There are trade offs. The topic is so broad we cannot even start to talk about it. Instead we start with what your application needs and then look at the options to get that.

Cast iron is fantastic for building machine out of - while it isn't as strong, it is stable against vibration. There is a reason engine cylinder selves are often cast iron.

I had some crappy cast pewter toys as a kid

Those were pot metal, not pewter (pester has many definitions but implies some qualty control). They are made out of whatever melts in a pot - often whatever is cheap at the recycle yard (without trying to identify what is in the metal - including lead which shouldn't be used in toys). Typically no control of the alloy was made and often they start with several different things that are great in isolation but when mixed result in bad behavior. Then the next time the make the toy they use different mix and get different properties. If you spend a little extra to get a known alloy pot metal is a high quality castings with great properties.

I’ve only seen the bargain bin results

You have likely seen a lot of non bargain bin results. However since the parts are invisible you never thought about it or the alloy used. You see the failures and so casting gets a bad reputation because it is obviously used in the cheapest things with low quality control. (the door knobs in your house are likely cast pot metal plated with brass, but they last for decades)

shiroiushi
0 replies
11h26m

Cast iron is fantastic for building machine out of - while it isn't as strong, it is stable against vibration. There is a reason engine cylinder selves are often cast iron.

I thought it was because cast iron had very high resistance to wear.

mrob
0 replies
1d2h

They also talk about forging. Forging can produce higher quality parts because metal has a grain structure. Just like wood, it's easier to break between grains than across the grain. Forging is deforming the metal without melting it. If the temperature isn't too high, it will deform the grain structure along with it. The grain can be aligned to make the metal stronger along the axis where it needs to resist the most force.

Wikipedia has a image of an connecting rod that has been etched to show the grain:

https://upload.wikimedia.org/wikipedia/commons/5/5c/ForgedCo...

You can see the grain has been stretched along the length of the narrow parts. Wrenches are another example of something that's commonly forged for this reason.

colechristensen
0 replies
1d1h

Cast iron is a material, it's good for what it's good for but its material properties don't really come from the casting process, just the ratio of iron to carbon.

Casting has problems with thermal expansion, plenty of materials shrink significantly as they cool and complex parts cool unevenly which can cause them to break or deform.

Casting has problems with microstructure, plenty of materials, especially steels develop complex crystal structures with multiple phases of materials as they cool from liquids and even extensively in hot solid phases. It's hard to control this in a cast part.

Casting has problems with precision. The molds just can't be all that precise when in machining, a thousandth of an inch can be a relatively large distance.

However casting gets a bad reputation because most of the time you see it it's because it's actually very cheap, cheap materials, cheap process, minimal post processing. Higher cost things don't necessarily realize the savings from casting as much so they don't use it. And also a lot of higher quality materials have higher melting points which require more advanced tools to melt and handle.

Plenty of things though are cast and then machined, you notice this if you look.

bagels
0 replies
1d1h

Other materials can be cast, such as various aluminum alloy. Casting can have a higher cycle time, be cheaper, and require a less expensive equipment.

WJW
0 replies
1d2h

Machining is fine, but in the context of the article the problem is that it usually starts off from plates or otherwise block-shaped materials. That means that if you have a weirdly shaped part full of holes and/or with many protrusions in weird angles (as vehicle parts tend to have), then you either have to combine many smaller parts into a final part or have to machine away a huge amount of material from a solid block to come to the final shape. It would be much better to cast or forge the part into roughly the right shape straight away, so you'd need only minimal finishing work. That is what these presses enabled.

jcgrillo
12 replies
1d1h

My little 20 ton shop press brake can bend 5/8" plate. Incredible to imagine what this behemoth can do...

kibwen
9 replies
1d1h

Using advanced math I hereby extrapolate that this 50,000 ton press can bend 12,500/8" plate.

jcgrillo
5 replies
1d1h

well the next time I need some 130ft thick brackets I'll ask them whether I can use it after hours or on the weekend

EDIT: or, according to hwillis' math, 2.5ft thick. I guess those could be useful for anchoring a zipline to the moon or something.

hinkley
4 replies
1d

I saw a guy weld 1.5 or 2 inch plate once to repair the bucket on a giant bulldozer. That was… interesting. I was trying to figure out why he left such a big gap until he started welding. He had to fit the head in to lay down layer after layer of welding bead to join the pieces at full depth.

How would you weld even one foot of steel?

hinkley
0 replies
16h50m

OMG. Are you required to slap it and say, "That'll hold" afterward?

jessebro
0 replies
4h57m

A lot of the armor plate on the big battleships like New Jersey were welded. Some of those are over a foot thick.

It would take a LOT of passes.

jcgrillo
0 replies
1d

For a butt joint V it out on both sides and do many, many passes. Maybe have a few guys with rosebud torches working heat into it as you go. Big rods make it go faster (https://youtu.be/j61ezBX-EyA). For a lap joint it's the same idea, you're going for a great big fillet. But if you have a gigantic press at your disposal there are other options. For inspiration: https://youtu.be/k_LA_R4ifYk

The idea behind forge welding is you get both parts nearly molten (e.g. "welding heat") then your hammer blow (or the pressure from a huge press) puts enough energy into the weld area to briefly melt it.

Also, hot rivets might be a better option than welding if you can get away with it.

hwillis
2 replies
1d1h

The second moment of area is quadratic with thickness (t^2), so 250/8" plate. But in reality 2-3x more than that, because at that scale steel gets a bit... goopy.

kristjansson
1 replies
1d

I understand very little about machining, expect that _all_ materials are kinda squishy if one applies enough squish.

mikewarot
0 replies
23h3m

Even inconel is bubble gum in a Kurt vise if you're chasing tenths, or microns.

PaulHoule
8 replies
1d1h

Nobody in North America has a press that can make a vessel for a nuclear reactor without making it in pieces and welding them together (probably adding a year to the schedule if you don’t use a new welding technique just developed in the UK not to mention people being anxious over the welds)

There is a Canadian company that is gearing up to make small reactor vessels like the BWRX-300 but so far I haven’t seen a sign they aren’t Nuscale 2.0

MisterTea
4 replies
1d1h

I work in an EB shop doing everything from welding, engineering assistance, machine repairs, and complete machine rebuilds. It's quite an impressive process and Ive had parts in my hands that come from some of the biggest names you can think of in aerospace, semiconductor, military, medical and more.

mensetmanusman
1 replies
23h20m

50 kW ebeam?

MisterTea
0 replies
20h35m

We have 7.5 kW and 15 kW machines. Smaller chambers but there's plenty of smaller work out there.

hinkley
1 replies
1d

Are they for prototypes? Or how do you service production runs for parts?

If for arguments sake it were a part for an AWACS or an aircraft carrier you might only need to make eight or a dozen. But even military aircraft tend to run into the hundreds.

MisterTea
0 replies
20h31m

We do production runs with the rare service run. Most parts are one time use as you might imagine. Service work is the rare mold repair.

We are part of a few companies just in time manufacturing so they pay for expedite processing on orders as small a one piece to a few dozen. And we can get production run orders in the tens of thousands.

PaulHoule
0 replies
1d1h

That’s it.

pfdietz
0 replies
6h58m

That is, a vessel for a pressurized water reactor. A reactor operating at lower pressure (like one using molten salt as a coolant) wouldn't need such a vessel, as the salt would not become highly pressurized, even in accident conditions.

I saw a link from some government minister in Canada named Don Morgan who stated a BWRX-300 would cost $5B (CAN), which comes to about $3.6B (US). $12/W (US) is not the worst, but it isn't great. Not clear if that was all-in cost or just overnight cost.

https://www.deassociation.ca/newsfeed/4-provinces-push-ahead...

shepherdjerred
6 replies
1d

What strikes me is how great of an investment this turned out to be. Does the US invest in manufacturing like this anymore?

Tangentially, if there were a war today would the US be able to produce as much as it did in WW2?

margalabargala
1 replies
21h23m

We didn't have any of these presses in WWII. We have several of the article's presses still operating today.

Furthermore, all presses mentioned in the article have been surpassed by a 60,000 ton press that opened in Los Angeles, in 2018.

People with agendas will happily feed others narratives about the US not investing in manufacturing anymore, but it isn't true.

US manufacturing output has been steadily increasing since always, with the occasional 1-3 year dip during recessions. However, manufacturing does represent a lower percentage of our GDP with each passing year, despite the absolute value increasing.

shiroiushi
0 replies
11h19m

People with agendas will happily feed others narratives about the US not investing in manufacturing anymore, but it isn't true.

It's a matter of perception. Most people don't directly see (or buy) the stuff manufactured in the US these days. Normal people don't buy nuclear power plants, aircraft engines, commercial aircraft, etc., and certainly not military hardware which the US makes a lot of. They do buy clothes and various consumer electronics, and they see "Made in China" (or for some clothes, places like Bangladesh or Vietnam or Cambodia) printed on all those, when 50 years ago all that stuff had "Made in USA" printed on it, or for the nicer consumer electronics 30-40 years ago, "Made in Japan". People still might be getting a CPU for their laptop computer manufactured in the USA, but the chip will probably say "Made in Malaysia" because only the silicon was made in the US, and was then shipped somewhere else for packaging.

However, manufacturing does represent a lower percentage of our GDP with each passing year, despite the absolute value increasing.

I'd say that's probably a bad sign: what other sectors are increasing? Likely they're things that aren't actually productive, such as healthcare (the value received does not represent the price paid in the US by a long shot, compared to other advanced economies; most of the money goes to insurance companies and waste), legal services, ever-increasing real estate valuations, etc.

bluGill
1 replies
22h11m

Does the US invest in manufacturing like this anymore?

No, but that is different from not investing. Today the US invests more in automation and engineering and less in manual labor.

if there were a war today would the US be able to produce as much as it did in WW2?

It took several years to ramp up to WW2 level production. We would see the same, a couple years of trouble on the fronts while building industry at home, then when the industry is built up massive production.

Historians (amateur so I'm not sure if they are right) tell me Hitler was ready for WW2 first and Italy begged him to not start the war as their industry wasn't ready. However France and Briton saw the war coming and were building their industry and so waiting might have made things worse.

shiroiushi
0 replies
11h15m

I wonder how history would be different if Hitler had told France and UK to f** off with the WWI reparations stuff, threatening a war if they tried military action to force payment, but then didn't invade anyone and concentrated on developing their economy and becoming a technological and manufacturing power.

waythenewsgoes
0 replies
23h57m

In terms of raw output, the answer is likely no.

However, this might not matter as much now as it did in the past due to nuclear weapons being the primary deterrent in war these days, and the fact that our standing fleet of aircraft, aircraft carriers, nuke subs, tanks, etc... is essentially second to none. Additionally what we do have is highly capable and extremely specialized, in my opinion, leading to not really needing as many (quality over quantity). Take for example, an F35, which doesn't really have an equal in the skies, we have over 630 of them, with the goal of having around 2500. China only has 300 J-20s which are basically a copy of the older F22. Russia only has 22 non-test Su-57s. Would we have a realistic need to build 1000 of them within a year?

Due to many factors, but primarily free trade and globalization, it's unlikely that we ever see that non-automated manufacturing capacity return, though if needed we could probably mobilize the economy via the defense act to force more manufacturing capacity, though it's hard to imagine we would currently need to.

bradford
0 replies
1d

Does the US invest in manufacturing like this anymore?

It might be easy to argue over the exact degree of similiarity, but I'd argue that the US has repeatedly made manufacturing investments since the 1950s. Buried in bills signed into law, you'll find such investments.

Recent examples include the Recovery Act of 2009 or the American CHIPS act of 2022.

https://en.wikipedia.org/wiki/American_Recovery_and_Reinvest...

https://www.cfr.org/in-brief/what-chips-act

advisedwang
4 replies
21h41m

This should be a lesson for free-market advocates, especially those who see the US economic boom as a result of laissez-faire economics. In reality there are opportunities the free market doesn't take, and wise government intervention can yield enormous benefit to the public.

mannyv
1 replies
21h5m

In reality what we call 'capitalism' is unstable and requires continual intervention to survive.

hackit2
0 replies
12h4m

That is a very simplistic perspective of 'capitalism', it is a bit more nuance than that. It typically requires intervention to prevent it from destroying the economy because of insider trading, liquidity, and monopolist practices. The only criticism you say about it mirror aspect of our-selves that we don't like to admit. It isn't perfect but people are not perfect how-ever based on how fast we're pull people out poverty, you have to admit its pretty good!

refurb
0 replies
6h56m

Do you feel that the free market wouldn't have adopted it at some future point in time?

eternauta3k
0 replies
6h39m

You may be right, but your conclusion doesn't follow from the article.

doormatt
3 replies
23h18m

The article says there's an 80,000 ton press in China.

kragen
2 replies
21h19m

many people in the usa say 'the world' when they mean 'usa'

retzkek
1 replies
20h47m

That's pretty ungenerous. The press release says "The press is the world’s strongest hydraulic pull-down die forging press in pit-mounted design" so it's easy for a layman to read "world's strongest ... press" and take that at face value.

kragen
0 replies
19h18m

i admit i don't know what 'pull-down' and 'in pit-mounted design' mean, and i'm not sure my understanding of 'die forging' is correct, but that seems likely

on the other hand, the press release might be written by the same sort of people who say things like 'the world series', which is a baseball tournament between teams from the usa (and canada)

https://www.gasparini.com/en/the-worlds-largest-hydraulic-pr... says

The United States leadership only lasted two years: in 1957 the Ukrainian company Novokramatorsky Mashinostroitelny Zavod (NKMZ), specialized in steelworks equipment, built two 75,000-ton presses. The first one, destined for a plant in Samara, is now owned by Alcoa’s Russian branch. The second was installed in Verkhniaïa Salda and is used by VSMPO-AVISMA, the world’s leading producer of titanium and other specialty alloys.

Outside the two superpowers, France was the third country to equip itself with a hydraulic press of this size: also built by the Ukrainian NKMZ, this 65,000 ton presse hydraulique* was installed in Issoire between 1974 and 1976. Owned by Interforge, the machine is 36 metres high and manufactures components for Airbus, Boeing, the space and transport industries.*

...

After 60 years, the USA has added a new 60,000-ton hydraulic forging press. Built by SMS Group and managed by Weber Metals in California, it started operations in October 2018.

The heavyweight champion, of course, is Chinese: a machine with the incredible power [sic] of 80,000 tons is in operation since 2013 for the giant Erzhong Group in the province of Sichuan. As tall as a 10-storey building, its use is very confidential: it seems to be used to build parts for military aircraft, like its titanic sisters. To give an idea of the power of this machine, with its 780,000 kN it could easily lift an entire cruise ship. As often happens, larger does not mean better: it is not the most technologically advanced press in the world. It was built by adapting old USSR projects from the 1980s, and is currently underused due to competition from the other giants we mentioned.

either this derives from this longer post from 02022, or they both derive from a common source: https://www.linkedin.com/pulse/worlds-largest-hydraulic-pres...

the owner was at risk of bankruptcy in 02015: https://web.archive.org/web/20160809080032/http://www.france...

nickdothutton
3 replies
1d

These massive presses are/were of strategic importance. Something politicians, most of whom seem to be lawyers these days, completely fail to grasp. I am not in general a fan of government subsidy, but I was very disappointed when the government of the UK declined to fund a large press in Sheffield, which would have been used to build the next generation of nuclear reactors. June 2010 timeframe. Luckily natural gas is cheap and has no geopolitical supply chain problems eh?

pjc50
1 replies
9h4m

We're not going to build the nuclear reactors either. The problem will finally be solved by re-permitting onshore wind and a lot of batteries imported from China.

(The "local supply chain is vulnerable to political uncertainty over long term project funding" problem is much worse in regard to trains, and has resulted in losing most of our train building capacity. See HS2 fiasco.)

elzbardico
0 replies
1h16m

This is basically a pipe dream. But as long as the subsides are going to Big Green scammers, we will have numerically ignorant journalists peddling this bullshit.

Dennip
0 replies
22h0m

Sheffield Forgemasters?

They are actually now directly govt owned as of 2020, with future investment for a new heavy forge.

a2tech
2 replies
22h31m

Howmet is an interesting company. My dad worked for them his entire life (it was called MISCO, then Howmet bought them, then Alcoa). He worked specifically in titanium injection molding--they would heat titanium until it was liquid and then force it under pressure into intricate molds they made onsite.

Most of the time they made turbine blades for jet engines, but if it was slow they would make golf club heads for PING and companies like that. In all the years he worked there, the golf club heads were the only tangible product of his work that I saw because everything else was tightly controlled in the facility.

chasil
1 replies
22h15m

The blades were actually perfect crystals, with either all the grain boundaries aligned, or no grain boundaries. This lets them run at higher temperatures without melting, increasing efficiency.

Pratt & Whitney appears to have developed most of the technology.

https://www.americanscientist.org/article/each-blade-a-singl...

dekhn
0 replies
19h35m

Oh, so that's what they were doing in the facility in my hometown. It was always pretty secretive and now I can see why.

azalemeth
3 replies
20h28m

If you're reading this article, you may wish to know that arguably a "counterpart" to heavy press forging is explosive forming [1] in which a chemical high explosive is used to force a template material against a template. The overpressure generated by the explosive can be equivalent or maybe even greater than heavy press forgings (a 50,000 US short ton force press exerts ≈500 MN force; peak overpressure close to detonating TNT or PETN explosives can be MPa or higher [2] so depending on the geometry of the part they may be comparable) and it has the added "fun" fact that complex cylindrical or spherical shapes can be made very easily and accurately.

The only people I know who have worked with this have used it to make superconducting magnets, explosively forming either titanium or high grades of nonmagnetic stainless (A4, which has µr ≈ 1) without causing marsenite formation due to machining. This includes a major international MRI scanner manufacturer, for one relatively niche product. It's like the "extreme" version of metal spinning [3] – forcing a rotating chunk of metal against a rotationally symmetric mandrel.

[1] https://en.wikipedia.org/wiki/Explosive_forming [2] https://www.researchgate.net/figure/Variation-of-peak-over-p... [3] https://en.wikipedia.org/wiki/Metal_spinning

kragen
0 replies
14h17m

*martensite

infogulch
0 replies
19h13m

There are some popular videos making spheres using explosive hydroforming, which is quite fun, and much lower tech than explosively forming magnets to avoid the formation of marsenite (sp?).

Animats
0 replies
10h28m

Explosive forming has been used to make aluminum boat hulls.[1] It's a useful way to form very large sheet metal parts.

[1] https://www.youtube.com/watch?v=CbS6rS0seuk

gffrd
2 replies
1d

By the early 2000s, parts from the heavy presses were in every U.S. military aircraft in service, and every airplane built by Airbus and Boeing.

The savings on a heavy bomber was estimated to be even greater, around 5-10% of its total cost; savings on the B-52 alone were estimated to be greater than the entire cost of the Heavy Press Program.

These are wild stats.

Great article! I was fascinated to learn about the Heavy Press program for the first time, here on HN[1] a month ago, and am glad more about it is being posted.

It makes me think: what other processes could redefine an industry or way of thinking/designing if taken a step further? We had forging and extrusion presses … but huge, high pressure ones changed the game entirely.

westurner
0 replies
20h51m

It makes me think: what other processes could redefine an industry or way of thinking/designing if taken a step further

Pressure-injection molded hemp plastic certainly meets spec for automotive and aerospace applications.

"Plant-based epoxy enables recyclable carbon fiber" (2022) [that's stronger than steel and lighter than fiberglass] https://news.ycombinator.com/item?id=30138954 ... https://news.ycombinator.com/item?id=37560244

Silica aerogels are dermally abrasive. Applications for non-silica aerogels - for example hemp aerogels - include thermal insulation, packaging, maybe upholstery fill.

There's a new method to remove oxygen from Titanium: "Cheap yet ultrapure titanium metal might enable widespread use in industry" (2024) https://news.ycombinator.com/item?id=40768549

"Electric recycling of Portland cement at scale" (2024) https://www.nature.com/articles/s41586-024-07338-8 ... "Combined cement and steel recycling could cut CO2 emissions" https://news.ycombinator.com/item?id=40452946

"Researchers create green steel from toxic [aluminum production waste] red mud in 10 minutes" (2024) https://newatlas.com/materials/toxic-baulxite-residue-alumin...

There are many new imaging methods for quality inspection of steel and other metals and alloys, and biocomposites.

"Seeding steel frames brings destroyed coral reefs back to life" (2024) https://news.ycombinator.com/item?id=39735205

twic
0 replies
2h3m

Electrolytic refining of iron, all the way from ore. Gets rid of blast furnaces, allows far more precise control over metallurgy.

mitthrowaway2
1 replies
1d2h

Not only is the giga press mentioned in the article, it's very far from being an equivalent to the Alcoa 50,000.

cbsmith
0 replies
1d2h

Yes, it is mentioned in the article, and it specifically says: "We can see a modern, obvious parallel between the Air Force Heavy Press Program and Tesla, which has created a similar revolution in car manufacturing by using large aluminum castings to replace dozens or hundreds of smaller parts."

So I didn't think what I said was out of line. Obviously, I was mistaken.

baking
2 replies
1d

There is no "H" in "Worcester."

mhb
1 replies
1d

And it's odd to see one there, since, from the pronunciation, you'd expect it to be spelled "Wooster".

mauvehaus
0 replies
23h4m

The Wooster in Ohio is spelled "Wooster".

Yenrabbit
2 replies
1d

For a program started in the 50s, it's impressive that "Six of the ten presses are still operational today."!

barryp
1 replies
23h10m

I got curious as what happened to the other 4. Wikipedia lists them as extrusion presses being scrapped in the 90's and 2021 in Maryland and Torrence CA. https://en.wikipedia.org/wiki/Heavy_Press_Program

I wonder if they wore out?, something better came along?, or just no demand?

SoftTalker
0 replies
22h24m

They've been maintained, wear parts such as bearings and seals can be replaced. You can keep well-made machinery running almost indefinitely if you take care of it.

urbandw311er
1 replies
19h27m

Anybody know: Do these large presses still exist usefully today or have they been obsoleted by larger ones / by newer manufacturing techniques?

ggm
0 replies
18h5m

TFA says some of these are still in operation.

sidcool
1 replies
2h7m

Love them or hate them. Tesla's manufacturing prowess is unmatched.

humansareok1
0 replies
1h33m

Given their seeming lack of proper quality control I find this statement highly suspect.

twic
0 replies
1h47m

Partly this broad range of uses for the heavy presses came from expanding the range of materials used in them. Originally the presses were designed to make parts from aluminum and magnesium, but by the 1960s they were not only pressing aluminum and magnesium but steel, titanium, nickel, copper, columbium, beryllium, and a variety of other metals.

Columbium is apparently an old name for niobium, and one perhaps still in use by American metallurgists.

There's no way anyone was making huge niobium forgings, though. Or nickel? Surely this is a reference to the use of those elements in superalloys.

nntwozz
0 replies
18h55m

The workers in those pics have no hearing protection, no eye protection; no helmets.

Yeah, must be the 50s.

My 75 years old carpenter is half deaf, his grandfather fell from a roof and died.

He himself fell off a roof in 1981 but was lucky and survived.

Just some thoughts seeing those men working in those conditions.

ckemere
0 replies
23h47m

Was reading this NYT op ed - https://www.nytimes.com/2024/08/19/opinion/chris-murphy-demo... - and reflecting that the people talking don’t get that the secret sauce for meaningful labor is not just that it pays, but also the sense that it is “special” somehow, in the sense that manufacturing parts with 50000 ton press is manual labor but also remarkable because of the uniqueness of the machine being used.

Most discussions about trying to build industrial capacity in the US seem to focus on either our high labor costs or on the disinterest in capital to invest in low margin places. I would love to understand what time frame of guaranteed business the government provided these companies to convince them to participate, and also what other industrial processes the government invested in which failed to take off. Specifically, why didn’t this sort of thing work for the solar industry a few years back?

brcmthrowaway
0 replies
21h57m

Is this how the SR71 was made?

Simon_ORourke
0 replies
11h50m

I'm not sure it's rose-tinted glasses or some sense of nostalgia for the "good old days", but it does feel that our manufacturing processes have taken a step backwards since then.

Nifty3929
0 replies
4m

Amazing achievement. But I can't help but notice how much we celebrate these efficiency gains in the past, while being scared of them in the present.

At heart, this is the story of using less labor to product a unit of output, and possibly also improving the quality of those units of output. This led to much better outcomes for society. Was anybody then scared of what would happen to the riveters? Maybe, but those voices would have been drowned out.

These days, production is demonized, particularly at scale. Is there any successful producer being celebrated for being so? Are there any new, innovative, labor-reducing technologies being celebrated?

Does it take a war to snap us out of our fear of being better?

Metacelsus
0 replies
1d2h

Now I want to see one of these on the Hydraulic Press Channel!