Blade steel help?

C

chiger

Joined
Aug 26, 2006
Messages
45
Probably not the place to introduce myself, but here goes. I’ve just got back in to building knives except for the occasional practice for a friend or kitchen piece for the wife.:barf: I call what I do building because I use the stock removal method and have not tried forging method…YET. I’m using w-1 and w-2 steels just because I know what to expect and ease of acquisition, plus they make dependable knives with proper tempering.

I see a lot of talk about 440C stainless as good knife steel, but I used it to build several knives back in the early 80’s and did not like it. It was designed for it’s heat and wear resistance, but if I treated it hard enough to get it to hold an edge…it baked out the silicone and lost its wear resistance and became hard to sharpen to boot. Ghost of Buck past huh? If I left it soft enough to offset this tendency…it would not hold an edge.:jerkit:

To the question…have the foundries re-formulated the steel enough over the last 28 years to fix these tendencies or am I just not skilled enough to use the steel?

Any help would be appreciated as I am trying to decide what other steels I would like to try.:confused:

Sorry if this is the wrong place for this question, but I'm a newbe!
chiger.
 
I have used a little 440C in the past couple of years, and I have had mixed results. Most of the blades were sent to Paul Bos for heat treating and perform better than I expected. A couple that were heat treated elsewhere were somewhat dissappointing. The blades from Bos are very resistent to corrosion and hold an edge pretty good. It takes a nice finish, as well. The others won't hold an edge as well, have developed minor chips in the edges in normal use, and came back to me a point softer than the blades from Bos. The edges were ground very thin, and this could contribute to the chipping factor, though. I finished the ones from Bos with a very thin convex edge and they haven't chipped yet. The others have a conventional sharpening on a flat grind. All of the blades (10 total) are from the same bar of steel.

All of that is to say that the heat treat is what matters most. I deal mostly with simple steels that I forge/grind and heat treat myself, and I don't know much about the technical aspects of heat treating air hardenning steels, but the limited personal experience I just described leads me to believe that the heat treat must be exact to get the most out of this steel.

The next time I use any stainless, it'll probably be CPM154.

Todd
 
Thanks Todd,

Helps a lot. The fact that they all came from the same bar says it all and reflect my experience. It sounds like the heat treat and temper still have to be hit perfectly to make it right.

And thanks for the CPM154 suggestion. Don't know anything about it, but I wil soon!

chiger,
 
'Baked out the silicone' ?? It would be silicon but you aren't going to bake it out ! If you have simple heat treating equipment and little knowledge of metallurgy stick to the simple steels. Stainless steels require the right equipment and knowledge to heat treat them properly and get the best performance from the steel.
 
440C toughness drops off quickly after 56 Rc. According to Crucible charpy data, it gets 26 ft. lbs. at 56 Rc and 16 ft. lbs. at 58 Rc. 154CM gets around 16 ft. lbs. at 60 Rc. According to wayne goddard, 440C, 154CM, and D2 are all about the same at the same hardness, since 154CM and D2 are tougher at higher hardnesses, they are better as far as edge holding is concerned. Polishing and sharpening are probably a little better with 440C, but not by much, and corrosion resistance is better with 440C than 154CM and D2. IMO, 440C was only ever used because it's the most commonly sold high hardness stainless.
 
Sorry I was so long about thanking you guys. Been out playing with new toy till the sketers ran me in.

Mete,
Heat treat was done by pros in what was state of the art climate control oven for 30 years ago. It had doors, they could add gas and everything. “Baked out” was just a idiom…like wire edge instead of rolled edge or burning the steel instead of describing the molecular process involved in carbon combination, which I could not do. Sorry for the inaccuracy in my speech. Just an old country boy from Kentucky.

Larrin

That tells me why I had trouble. Since I didn’t know anyone doing what I was with 440C back then and the machine shop doing it had no experience with the application we didn’t understand the drop off after 56C. I just went from one extreme to the other 60 Rc to 32 Rc trying to get noticeable results with no regard for the middle. I liked working the steel but just got frustrated after 10 or 12 knives. It sounds like if I keep it around 50 Rockwell I can give it another try. Very useful Larrin, thank you.

chiger
 
Chiger

440C isn't going to hold an edge very well at 50 Rc. Bos shoots for 58-59 Rc, I think. Mine came back from Bos at +/-59 Rc. The others came back at 57-58 Rc. The ones from Bos hold an edge better, finished easier, and haven't chipped (the edge profile is different, but not any thicker) in the same type of use. Most everyone is going to shoot for the high 50s with
440C.

With a quality heat treat, I think you'll be satisfied with this steel at 58-59 Rc. It won't hold an edge quite as well as some other steels, but it's very stain resistant and is pretty easy to sharpen with conventional methods. It finishes nice, too.

Edited to add: Where are you in KY? I'm in the Bardstown/Elizabethtown area.

Todd
 
Chigger, I second the motin on CPM 154. It is a lot like 440C in grinding and finish, maybe a little nicer to finish. The performance will be noticealby better and it is easy to get hardness 58 to 60. You can get it from POP's knife supplies and he has a selection of thickneses.
706-678-5408. His prices are competitive with buying it direct from Crucible and you can get small amounts. Paul Bos will do a great job heat treating it. Phil
 
Thanks Todd,

First…Cool. I’m a ‘tween the rivers boy, Trigg County for the rest of the world. Been to Bardstown and E-town many times. Great to live in the commonwealth, huh!

Now to your post, I think I am beginning to figure this out. The data Lerrin shared dovetails to what you are saying. It also confirms that my original experience with the steel 28 years ago was just the nature of the beast. The 32-38 Rc pieces were completely unacceptable. The higher hardness 58-60 Rc pieces I did wouldn’t hold an edge any better than the home treated W-1 and W-2 carbon steel pieces I’d done and the SS were a lot bigger pain to sharpen. No problems with chipping or anything just disappointed with the performance for all the trouble it was to produce a SS knife back then. They were rugged, good-looking knives…I guess my expectations we just a little to high. I though I was making Super Knives and they were just good. Ahhh, it’s all starting to come back to me…

I’m looking into Todd’s CPM154 recommendation, but it’s beginning to look like I may stick with none stainless for a while unless someone comes up with a SS that I can home treat with some sense of accuracy.

Thanks for the input Todd. Any and all suggestions will be greatly appreciated.

chiger
 
Thanks Phil,

I’ve started researching the steel and my next step was to look about suppliers and availability. You are the second person to say that. I may try it for some special knives I've been thinking of trying. Is it suitable for big fixed blades?

ps. thanks for the supplier info.
chiger
 
Dumb question awnsered Phil,

Just found a 6 inch Chefs knife from Butch Harner of CPM154 that just listed and its a knock out.

chiger
 
Chiger, yes I made a Chef's with CPM 154 for my own kitchen and this is a "big" knife on the scale of things I work in. My suggestion would be to get enough for a couple of knives from POP and get the heat treat done by Paul, and try them out. I'm sure this will restore your confidence in making knives and SS for blades. By the way I know what a chiger is, I lived in Tennessee when I was much younger, my Dad was in the Air Force so we moved around a lot. I used to get chiger bites walking in the woods and on hikes with the Boy Scouts. Itches like crazy, worse than a mosquito bite. PHIL
 
Hi Phil,

I think I will try you guys suggestion. Looking back through the benefit of age I think I may have had some unreal expectations.

And yep, you got it right. Chiger (southern spelling not correct spelling) is a way of paying homage to may father. His nickname when he was a kid was chiger and from what my uncles tell me…it fit.

Thanks,

chiger
 
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