heat treat guru`s I need your help....

S

Scott Fulford

Joined
Feb 16, 2002
Messages
91
Not knife related but gun related and just as much fun in my opinion.
The problem is......many guys are building AK-47 style rifles from parts kits and U.S. made recievers(completely legal-you have to buy the reciever from a dealer with background check etc...)The recievers are not hardened! some have made rifles with the soft recievers and have had no problems but many builders want to do it right.
Here`s the reciever...
akm-rec_s.jpg

I believe the recievers are 4150,the trigger pin and hammer pin holes have been "induction hardened" but many feel that the whole shebang should be hardened and tempered to 45 rc or so.
How would you do it?How would you do it if you didnt have a knifemaking shop and only intended to do one reciever?
How hot does the temper have to be to get to 45rc?
Do we quench in oil?
Oh,yeah the recievers are 1 to 1.5 m.m. thick sheet steel,presumably 4150 but I could be mistaken on the steel type.
The debate is here.....http://www.gunsnet.net/forums/showthread.php?s=&threadid=108760
Any and all help would be greatly appreciated.
Thanks,
Scott
 
If I were to want to do something like this and do it right, I would contact a heat treating company that handles the material the reciever is made of on a regular basis. Have them anneal the recievier 1st to make sure it doesn't warp from forming ,welding,or induction hardening. After that have em go ahead and heat treat it to the specified hardness. Maybe doable check with a custom gunsmith that builds recievers(not just someone who assembles parts). You might get some answers contacting Vector Arms. They are building US UZIs with heat treated recievers and I would assume they would know the whys and hows. Good luck :)
 
You must be certain of the steel type. I would contact the vendor and verify. Upon doing that, contact Douglas Barrel and ask their advise as to wether they may be willing. They heat treat all their own work. They have a web site and I think I have them linked on my site (click picture below and go to links page for Douglas Barrel).

It may be 416. Check with the vendor.

Roger
 
I seriously doubt if it is 416 (too expensive)

But like it was said above, YOU MUST know exactly what steel is involved before you proceed.
 
Scott,
It sounds like you may be interested in doing this HT yourself? I wouldn't recommend it. Here is why...

For starters, like the other guys said, you absolutely must find out what type of steel it is first. You must. Also you could complicate things real fast in that type of part if you don't use an oxygen free (or near free) atmosphere. I.e. gas, foil, salt, etc. Especially at that thickness. Scaling will compromise your dimensions. Are these parts normally hardened or hardened to 45HRC? Induction hardening is done usually only on parts that MUST, at least have a specific area hardened. The unhardened parts are either negligible or benefit from the soft, toughness somehow. Or in some cases, a compromise to avoid warpage in fully hardening a part. It may be a more economical method for the maker. Depends on different things. So, this may effect any necessary or unnecessary heat treating. The advice already given is what I would say to do as well. These are just some reasons you may run into should you do this yourself. Good luck on your project.

Jason
 
dont try it with a stamped receiver. a milled one you could probably get away with, but i would imagine a stamped one would warp enough to where the pins werent lined up right. any change in this could cause the trigger, sear, and hammer to not function correctly.

i would imagine that spot hardening around the pins would be fine. hell, an AR15 receiver is aluminum, and the pins and holes do just fine.

i wouldnt worry about it.

Edited to add:

you dont in fact NEED to buy a receiver from a dealer. ive seen folks make their own and have them work. not that i would really be comfortable having a homemade receiver operating at pressures of about 60,000 PSI next to my face.

but aparantly some folks are ;)
 
The fact that these parts have been induction hardened says quite clearly that they are already in their finished (from a heat treatment point of view) state.

Any additional heat treatment will undo the induction hardening and most probably warp the part.

A "do it yourself" heat treatment of an unknown steel in a critical part like these recievers is a good way to kill yourself.

Avoid the award.
 
Well,firstly it`s not me thats doing this,I was just asking to help out guys who were,I have 3 AK`s already,factory built.I did build an AR-15 from a kit but there was no HT involved.
Thanks for all the help guys.
Scott
 
yeah, building an AR is the way to go if you're gonna build a rifle. the US made receivers are WAY better than any US made AK receiver plus the platform is more versitile anyhow.

but i'm still an AK man at heart ;)
 
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