Knife made out of 4140????

CKE2 · Sep 16, 2003

At work we use 4140 for all sorts of things. It is shafting but obviously can be milled to shape. Will this make a good steel to make a knife out of. I have the hardening info to get it to about 58Rc. I know this stuff will rust but I wonder if it will work for a tough fixed blade??? Making sure to keep it clean and to not let moisture work on it. Thoughts???? Take Care!

C L Wilkins · Sep 16, 2003

4140, also referred to as F5 is a chromemoly steel primarily used for flanges and pipe fittings around industry. It is also good for making dies and whatnot for hydraulic presses and maybe even hammers. In essence, it may a good for impact resistance but to be quite honest, I haven't ever heard of a knife made from the stuff.
It doesn't mean it can't but I just haven't heard of it in that application in my limited experience.

I am only familiar with it since I used to work on the instrumentation side of the industrial heat treat and forge side of the business. Ironically, this was before I was interested in knifemaking.

Craig

Bladeandbarrel · Sep 16, 2003

Original Becker Knife and Tool Machax's (pre blackjack) were 4140.
They were really tough and never broke.
They really weren't awesome edge holders IIRC.

rdangerer · Sep 16, 2003

4140 contains:
.40% carbon
0.50% - 0.95% chromium
0.12% - 0.30% molybdenum.

Pretty simple stuff.

As a comparison, 5160 looks like this:
0.56-0.64 carbon
0.70-0.90 chrome
0.75-1.00 manganese
0.15-0.3 silicon

I'd guess 5160 will get a bit harder, and is probably a bit tougher.

4140 would make a simple low carbon knife blade. Somewhere in the neighborhood between 1050 and 5160.

(I'm not a metallurgist though... grain of salt).

J. Neilson · Sep 16, 2003

I haven't heard of it for blades but, I bet you could make one heck of a nice 'hawk out of it.

mete · Sep 16, 2003

Back on 7-27-2003 Sylvester posted for me my miniature tomahawk, it's forged from 4140 !! This is a great steel with applications from rifle barrels to aircraft but it's carbon content is a bit low for a good knife.

Danbo · Sep 17, 2003

I wouldn't want a knife blade made out of 4140, but it sure would make a great anvil.

Disco Stu · Sep 17, 2003

I've always been under the impression that anything under .5 percent carbon won't harden well. I guess throwing in that chrome and moly make the difference.

CKE2 · Sep 17, 2003

Thanks folks. Have thought about the hawk somewhat but thought a blade first. We'll see thanks again for all the help! Take Care!!!

tique · Sep 17, 2003

If I remember correctly, my RMJ Forge Eagle Talon is made of 4140, awesome hawk in the hand... Sadly I haven't had a chance to take it out and beat it up yet, but have heard nothing but good things from those who have.