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Looking for 4032

Posted: Sat Jul 06, 2019 8:55 pm
by Slipped Eccentric
Hey all, I'm looking for about 4" of 2" dia. 4032 aluminum in order to make a piston. Any leads?

Re: Looking for 4032

Posted: Sun Jul 07, 2019 10:14 am
by Inspector
Some here but don't know if they sell small amounts. https://www.eaglealloys.com/4032-aluminum/
Pete

Re: Looking for 4032

Posted: Sun Jul 07, 2019 1:34 pm
by rklopp
I found 4032 round bar on Amazon, but I don’t see sizes listed, nor “Add to cart,” which makes me think it is not truly available. I could swear I bought some from McMaster years ago, but they don’t seem to list it now.


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Re: Looking for 4032

Posted: Sun Jul 07, 2019 3:00 pm
by Russ Hanscom
How critical is that particular alloy? It does not appear to be a common one.

Re: Looking for 4032

Posted: Mon Jul 08, 2019 12:10 pm
by Slipped Eccentric
Thank you for the help so far. I've found eagle but don't use aluminum nearly enough to justify buying a whole bar and keeping it around. Similar issues with Amazon and it not being in stock. I guess the actual alloy isn't that important, but it's going to be a piston in a scooter that will see some use so I want something that will hold up. From what I've found this is what's normally used due to its high silicon content, so if anyone knows of a similar more readily available alloy I'd get that instead.

Re: Looking for 4032

Posted: Mon Jul 08, 2019 3:33 pm
by Harold_V
I would think that 6061 in a T6 condition would do the job satisfactorily, and it's readily available.

H

Re: Looking for 4032

Posted: Wed Jul 10, 2019 7:24 pm
by John Hasler
Harold_V wrote:
Mon Jul 08, 2019 3:33 pm
I would think that 6061 in a T6 condition would do the job satisfactorily, and it's readily available.

H
A direct comparison of 4032 and 6061:

https://www.makeitfrom.com/compare/4032 ... 1-Aluminum

Re: Looking for 4032

Posted: Wed Jul 10, 2019 11:44 pm
by armscor 1
Silicon content is the problem with 6061, not enough, too much thermal expansion, JE piston company give a good explanation why they use 4032 for their cast and forged pistons.

Re: Looking for 4032

Posted: Thu Jul 11, 2019 1:45 am
by Harold_V
The issue with expansion is far more critical for internal combustion engines than it would be for steam, where temperature swing is reduced considerably. 6061 will serve adequately, especially considering the diameter of the piston is likely small (certainly smaller than the typical internal combustion automotive piston).

H

Re: Looking for 4032

Posted: Thu Jul 11, 2019 9:09 pm
by Slipped Eccentric
Harold, this is for a 2 stroke scooter. Finished diameter would be 45mm. The only other option we have right now it to knurl a piston and it will still be slightly too small.

Re: Looking for 4032

Posted: Thu Jul 11, 2019 10:18 pm
by Harold_V
For what ever reason, my mind had gone to a steam engine piston. Now I understand. I suspect the engine in question it's also air cooled, so temperature is certainly an issue.

A rather energetic project, but one could cast a piston if really needed.

Regardless of the material source (cast or machined from bar stock), I don't know how you'd address the cam grinding of the skirt. Did you intend for it to be round?

H

Re: Looking for 4032

Posted: Fri Jul 12, 2019 1:37 am
by LIALLEGHENY
Contact McMaster Carr. They no longer list 4032 in their catalogue, but that doesn't mean they don't have it or can't get it for you. I have bought items through them that were not listed. Tell them what you need and they will source it for you. You may have to buy a 12" length or a minimum but they will get it for you.

Nyle