Cpm154 how thin

bikermikearchery

bikermikearchery

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Jan 18, 2007
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I usually stay with oil hardening steels. However I took a commission for a knife for a Yacht club There going to raffle at there annual banquet. Hmmmm Knives for salt water. So I'm using cpm154 and sending it out for heat treat. How thin can I go on the edge before heat treat? Any other suggestions for this metal?
 
Com may not be the best choice for a salt water knife. It only has 14% chromium and will rust in harsh conditions, a 440 family member may be a better choice.

Im not trying to deter you from cpm154 but salt water is hard on a knife.

If your sending the knife to Paul then 1/64" would be fine, if you want to play is safe 1/32" more than suitable.
 
I work with cmp154 as my main steel, on small knoves i will take the edge down to .020
befor heat treat and sand to400-600 grit.a good HT should get them back to you looking almost as you sent them.I do my own HT and have very little clean up after.
Stan
 
While I don't disagree that 440C has pretty much the highest corrosion resistance of the steels that we use, I think that 154 will be fine around salt water, especially if you take it to a fine finish and passivate it with acid.

Mike - why not just send the blank out and then grind it afterward? That's what I'd suggest if you're working with a belt grinder.
 
I too take mine to .020, but I I'm sending out a 3/32 thick piece for a filet knife to Paul Bos. I've only profiled it and won't grind it until after heat treat. Anything thicker than that though gets the .020 thick.
Had to edit my thickness, wasn't paying attention there. Thanks again Nathan the machinist
 
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I agree that 154CM and CPM 154 are at least rated as superior to 440C in almost every regard - including corrosion resistance. I haven't had a problem with any of them rusting after proper heat treat.

As for edge thickness, it's a good question - especially given the steel you've chosen. We all know a thinner edge cuts better but that there is a trade off with edge durability. CPM154 is twice as tough as regular 154CM at the same hardness, so you can safely take it thinner without compromising the edge durability.

As for heat treatment, blades today come back cleaner than ever - and require very little additional finishing. I ask people not to, but many send me blades sharp enough to shave hair. They go back the same way without noticeable damage to the edge.

I think .010 edge would be a good target.

Rob!
 
Thanks all for the answers. I understand that I can run the blade to a near finished condition. :)
I chose CPM154 over the 440 because I believe it makes a better cutting tool.

These guys are yachts men not necessarily divers. I hope that I can convince a person who is willing to re-varnish his Teak decks every year, to wipe the water off his knife.:rolleyes: OK maybe thats wishful thinking.
 
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