I have been reading in other forums that 4140 van reach an rc of 59-62 when super quenched and hold an very well no matter the grind you put on it. I was wondering whom else has had experience with this because that seems wrong to me.
I have quite a bit of experience with 4140 just never used it for knives. The highest Rockwell I've seen is about 52. Definitely not a good blade steel but it is a great steel for making certain tools because it can be hardened thru or flame hardened and it is fairly inexpensive
it sounds like maybe someone case hardened a piece of steel and thinks they have the new miracle steel for knives. Best to leave that steel to pressure vessels and airframes
It would probably even make a pretty good anvil. Also nice for dies for a shop press. I made a machinists vice out of it a long time ago. One problem with 4140 to keep in mind is that it does rust very easy
Aircraft used to have boiled linseed oil inside the airframe tubes, pour out the excess and weld the tube shut.
4140 would not be my choice for knives but there are a few places it does shine. Stake anvils, dies, punching tools, drifts, and hammers are some common uses that it seems to be suited well for. Another common use is in hard use tomahawks and axes as well and breaching and entry tools.
I've seen a few gun parts made from 4140, but 4150 is more desired, especially for gun barrels. As a matter of fact, I had a .22 in my possession at one point in time that had a receiver made from 4140.
Thanks Griz, believe it or not I was wondering what parts were made from for rifles and really did not feel like filtering all the junk on Google
No problem, John. Lots of accessory stuff is made from 4140 as well... like scope rings, weaver & picatinny rails (when aluminum or polymer is not desired) miscellaneous hardware, and yes, even some receivers. I'm not sure what my CZ858 is made from, but it's certainly steel, and probably specced similar to 4140 or 4150 since it's a milled receiver.
Good stuff to know in case I ever get asked to heat treat a rifle part, last time I played with rifles was mounting a scope on a FN-FAL and drilling out a 12ga barrel to make a home made muzzle compensator
Not a lot of guys make their own gun parts these days. If I had regular access to a milling machine, I'd have a few things I'd be happy to farm out.
