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Need a source for 4340HT rounds Rc42

bastarddsm

Aluminum
Joined
Feb 18, 2014
Location
Southern Illinois University
Hi,

Does anyone know where I could find some 1-1/8 4340 or 300M rounds that are pre-heat treated to Rc42ish. What is the maximum hardness that can be machined with normal insert tooling?

I have a job to make a set of axle shafts that are splined on each end. Spline major dia is 1.0625, and minor is somewhere around 0.987", and 22" long. I don't have a ton of material to remove.

Any other material I could look at? I need 200ksi+ tensile, and I'd prefer to avoid sending it out for heat treat. I found ETD150 (not strong enough), and Flexor - M. Flexor-M looks ideal, but I can't seem to find it anywhere, and it sounds like it can be a pain, with it moving around during machining. I only need a couple of 2 foot bars at this point.

Also, I'm aware the splines should be involute and induction hardened to the the mid 50's... but, this is an extreme drag application that is not going to see any real mileage, uses old used outer CV's that are already worn, and this will likely break the bars I make in time anyway.
 
You shouldn't have much problem using properly chosen carbide inserts for steels up to low 50s RC. Slow your surface feet, keep your setup as rigid as possible. For your needs, if the axles are straight a follower rest may help, if tapered then take light cuts and be prepared to change insert tips more frequently.

Depending on the grade an air blast may serve you better than flood cooling.

You also may find that a precision shot peening will extend the life of the parts by putting off crack initiation. But it must be done correctly, improper peening could warp the axles.
 
You could also check out 9310 steel, it might work well for you.
I would disagree with this. I love 9310 but for this purpose, you need max ductility.

If you want to go crazy, Vascomax. Comes in 250, 300 and 350 kpsi and ductility is (iirc) about 18%. Magic. No quench and temper either, solution hardening. That's what we used for input shafts on unlimited-boost turbo Offies. I think they were getting over 900 hp out of a four-cylinder. Not too smooth on the power pulses :) It was a big secret at the time but we had some famous names buying input shafts cuz ours didn't break. Ever. It wasn't because Web was a genius. Material did the trick.

Otherwise, 300M is the bee's knees. Just heat treat it after. Make them hang it vertical for quench. Those UOP Shadow Can-Am cars ? 300M. Good enough for George Follmer, good enough for me :D
 
I would disagree with this. I love 9310 but for this purpose, you need max ductility.

Toughness. And depending on H/T, you can get it from 9310. I'd also point out the OP is at Uni and likely isn't made of cubic dollars, so a rationally priced material can help.

And he knows he's going to break things, that's what drag racing is all about - throw money at broken parts, assemble, repeat...
 
We use a lot of 4330V-mod. in place for 4340. The problem you're going to have is getting it in the heat treated range you want. Just not going to happen for stock items. The other problem could be is getting it in the small diameter needed. There materials usually don't start in sizes below 3" OD. Check with some of the steel suppliers in Houston. They usually have a better stock of sizes of this material for oilfield applications. KenS.
 
I knew of vascomax, just figured heat treating was a pain. Looks like it's not bad, but holy cow on the price. I'm just beginning this journey of making parts for money, so I don't really have connections for materials. My go-to's are speedymetals, and Mcmaster.

I never thought of 9310 for axles, I didn't think it had the core strength near 200. It looks like it'll go 180ksi, but I can't tell if that's as delivered or after heat treat.

That toolox 44 looks like it might work, but where do I get it?

I'd really like to try the flexor-m stuff. But where do I get it? Do I just call Penn Steel?

Now for the rest of the story:

This is really for a buddy, and the car has had a larger tougher rear diff installed, and now needs new bars to connect to the stock outers. When it was all stock, they kinda held up, at least for a half dozen passes. When it would break it was always a crapshoot whether it was a bar, an inner, or the diff that would break. The outers seem to hold up way better. So now with a bigger diff, bigger inners, and hopefully a better bar, it should be better, but it's probably still limited by the outer, and the slightly smaller spline on the outer end of the bar. Doing the engineering, and assuming worst case, it says rear bars need to be 200ksi or better. I doubt stock ones are anywhere near that, but it's hard to tell what they are made of. Anyway, it's sort of a cottage industry I'd like to get into. Making one off axle bars for little 4cyl import drag car stuff. A very very tough part of that industry is that it's very much built on hype and buzzwords. 300M is one of those buzz words, everyone has to have it even not understanding what it is or any downfalls it may have. So if i can find an alternative thats "better", and this goes on my buddy's car - that should set the world on fire - that's very very good for me. I feel like Flexor might fit that need.

As for me, yes, in the last little bit of finishing my PhD in ME. Working the side hustle as much as possible so that when I'm finished, I'm ready to hang the shingle, and have a decent head start on it.
 
The OP is prolly in the hot rod group down at Southern, they take some cool stuff up to the Rt 66 show up in Springfield in the fall (cook some good food too).

4340 @ 42Rc will be under 200Kpsi but it’s still strong. 9310 is tough as hell but works best when the outside is jacked up by carburizing.

Finkle has some stock stuff that sets around the 200Kpsi number @ 43-46Rc. The WF-Xtra in the middle below has .42C-.75Mn-.50Si-.80Ni-1.0Mo & .05V in the #1 temper condition gets you 205Kpsi @ 80°F. The chemistry for the FX & WF are on the flyers. The home plant is in Chicago.

Good luck,
Matt
 

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AerMet 100 and Ferrium M54 $$$$
What they neglect to mention is that those are about equivalent to the weakest version of Vascomax ...

And the heat treat is quench and temper instead of an easy 900* solution hardening .... could do it at home in your self-cleaning oven :D

What's the price on Ferrium ? Claim is it's supposed to be a cheaper replacement for Aermet 100 ....
 
What they neglect to mention is that those are about equivalent to the weakest version of Vascomax ...

And the heat treat is quench and temper instead of an easy 900* solution hardening .... could do it at home in your self-cleaning oven :D

What's the price on Ferrium ? Claim is it's supposed to be a cheaper replacement for Aermet 100 ....

Just adding to his selection, not trying to one-up Vascomax. I love the maraging steels (for the reason you mentioned).

I, also, saw Hy Tuff in those charts. Was it Henry's or Summers Brother's that used to use that stuff?
 
What they neglect to mention is that those are about equivalent to the weakest version of Vascomax ...

And the heat treat is quench and temper instead of an easy 900* solution hardening .... could do it at home in your self-cleaning oven :D

What's the price on Ferrium ? Claim is it's supposed to be a cheaper replacement for Aermet 100 ....


The standard aging treatment for AerMet 100 alloy is 900° F +/- 10° F (482° C +/- 6° C) for 5 hours.

from the pdf

https://www.ssa-corp.com/documents/Data Sheet AerMet100.pdf

The min uts for Aermet 100 is 275ksi upto 310ksi per MilHndbk5 so quite a bit stronger than Vasco 200 and 250
 
thanks for the suggestions, but where do I get small quantities of aermet or vasco300.

Fry Steel has aermet 100 and vasco 300 listed on their site, whether they have it in stock is another question. They will sell you 1" or 12'.

Sit down for the price.

One thing we found at the last job is that Aermet 100 and maybe vasco300 can loose carbon in the approx .015 outer layer of the part. we used to heat treat and then machine .02-.03 to remove the decarburised layer. You can also shot peen after heat treat to over come the defiencies of the decarbed layer. There's a NASA paper out there which details experiments and solutions to the decarb issue which has a great effect on fatigue life. We didn't have a vacuum furnace, but ht'ing in a vacuum furnace would minimise the problem
 








 
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