Opinions on 12L14 steel for lock parts

[44-henry]

I have come across a good supply of 12L14 steel barstock and am curious if anybody on this forum has any experience using it for lockparts (screws, tumblers, sears, etc). Obviously I would caseharden it before service, but I am wondering on how the high lead content will impact the casehardening effectiveness.

[jerrywh]

You can make anything except the springs out of 12L14 if you case harden it afterwards but I would prefer 1018 or some unleaded steel if it were me.

[44-henry]

Thanks, that was kind of what I was thinking. The stuff cuts like butter in the lathe, I'll probably reserve it for screws and such.

[Dphariss]

I have come across a good supply of 12L14 steel barstock and am curious if anybody on this forum has any experience using it for lockparts (screws, tumblers, sears, etc). Obviously I would caseharden it before service, but I am wondering on how the high lead content will impact the casehardening effectiveness.

It should work fine. All varieties of steel has good and bad qualities depending on the usage. It should make good lock parts if case hardened. I have a case hardened 1018 tumbler in my 16 bore that has stood up to quite a bit of shooting with no changes.
Mild steel casehardened actually has some advantages over tool steel etc for lock parts.
It will make great screws since this is what it was "designed" for.
I have casehardened hundreds of screws made from this with a propane torch and Kasenite and once in awhile one will chip at the "corner" of the screw slot if not drawn back to blue for finish color.
Dan

[JCKelly]

For tumblers I might suggest you are better off with 1018, casehardened. The sulphur & phosphorus in 12L14 make it brittle, hence your scear notches will not hold up so well.

I'd not use it for screws, either.  They tend to shear off like hard cheese when torqued too much.

The one and only purpose for this grade is to maximize production rates on automatic screw machines. That does not mean those screws are good, but it does mean that they are competitively priced.

[44-henry]

Any opinions on 8620? I've made a lot of parts with 1018, but the stuff doesn't always machine as well as I would like.

[billd]

Many say 12L14 is only for screws. My shop uses lots of it for hydralic components. We make the mast and cylinder components for one of the largest fork truck manufactures in the world. It case hardens well, just don't try welding it.
 

[Dphariss]

I'd not use it for screws, either.  They tend to shear off like hard cheese when torqued too much.

You mean like the hardware variety wood screws that like to twist off in the hole?
The screws I referenced were made in screw machines and I assumed thats what they were. But they were pretty tough so they could have been some other low carbon steel I guess.

Dan

[JCKelly]

Mr. 44 Henry--8620 is nice tough stuff, usually meant to be case hardened. Doesn't have to be hardened, you can use it for screws & breechplugs in the annealed condition. The nickel, chromium and molybdenum content that helps make it tough also makes it less pleasant to machine than 8620