Preferred steel for kitchen knives?

[jmforge]

CPM M4 has shown up on some production knives from Spyderco, IIRC. It is very tough and incredibly abrasion resistant. That makes it hold an edge for a LONG time and also gives the edge great stabillity even when taken down very thin. The problem with the stuff is that it is so wear resistant once it is hardened that you had better be satisfied with a machine finish and be willing to use a belt grinder and diamonds stones to sharpen it because thats apparently about the only way you can touch the stuff. I got a chance to talk to Warren Osbourne and a couple of other others guys who first used the stuff in comp knives a few years back at the Knifemakers Guild show. They raved about the stuff, but said it was a bear to sharpen. The one thing that I did find very interest was that because the stuff will hold such a fine edge under the torturous conditions of comp cutting, they were able to reduced the thickness of the typical comp knife a fair amount and pretty much eliminate the distal taper which put the weight out front, but also made the "sweet spot' where the blade cut/hacked bet much larger. M4 might be a bit too difficult to work with for the typical thin pro kitchen knife, but it would make a hell of a cleaver for sure.

Wow this thread got pissy fast. You knife guys are an odd bunch.

*******, tell me more about the M4. I saw somewhere a hardness versus toughness graph and it looked like it would have excellent potential for edge retention. I understand the difficulty in sharpening tradeoff but I would guess that once you got and edge you'd be good to go

-AJ

 

[Daniel Fairly]

This is an interesting thread. Watching all the "new guys" interacting, lol. I'm curious as to precisely what a "thicker spine" means and what exactly this "tougher stuff" is that requires it. Are you suggesting that a 3 mm spine is ideal? If so, where are the spine would you be taking that measurement? Exactly what was your "go-to knife" as a chef?

I'm just a newbie to the world of high quality kitchen knives and I was excited so see my favorite supplier with a steel that looked good.

The spine is the opposite of the sharpened edge, I like them on the thicker size for some knives. I'm not really sure why this is controversial to say this, I'm not trying to say I make the best kitchen knife or something, heck I haven't finished one! The 5/32 was the thinnest 52100 I found and I thought that could be a little thick for some people but I thought it sounded fun. The ideal knife is what is good for the job.

Lol, I'm not some celebrity chef or something, just some dude who worked in kitchens for maybe 10 years. I had what I thought was a decent knife at the time, a Wusthoff Wide Blade chef's knife. Lol, it cost me $100 back in '94 when I was making $8/hr and I thought it was a good knife. I now know that it could have been a whole lot better! I liked this knife for prep but it wasn't ideal for all tasks, I had a revolving assortment of other knives I liked for delicate slicing and boning or filleting.

When I referred to cutting up "tougher stuff" I was talking about half frozen chickens and that sort of thing. I used to prep about 100 half frozen chickens into 8 piece every weekend at this one place, when my hands would get half frozen and tired I liked my thick chef's knife as the larger surface area of the thick spine was more comfortable.

 

[Daniel Fairly]

Fairly said "As a former chef I like a thicker spine for pushing through tougher stuff...". Those are not activities a chef needs to care about. TK was asking what he preferred a thicker chefs knife for and what an ideal spine thickness would be for him.

I think for joints and cartilage I like the thicker spine design, maybe 3/16? The wedge shape is nice for seperation also. It certainly is not the only or best way to go, it is just what I like. For vegetables and cutting food that goes on a plate on the line I would prefer a thinner spine, maybe around 1/8". Once again, just my opinion.

 

[Daniel Fairly]

Here is my first attempt at a kitchen knife, it is an odd one to say the least. I ground it out of .049 15n20 steel and it has some 3/8" black paper micarta scales and stainless pins and is 12" long. The tang is exposed and it really serves no purpose, lol my scales were too short and I always do an exposed tang so I thought what the heck. It has a "short" convex chisel grind!

I did some minimal slicing and I was impressed, I was able to slice a banana just about paper thin! I also tested the heat treat by going all out on some seasoned 2x4's and it passed with flying colors, I was actually surprised by the performance, it was downright scary!

I only used the .049 15n20 because I had it laying around and I thought I'd try something different, it seems to be on the thin side to me.

Second from the top.

 

[obtuse]

I've been interested in how steels like 15n20 perform on their own.

 

[HHH Knives]

Cool looking knives Dan.. If Im not mistaken 15N20 is essentially 1075 steel, with a 1.5% nickel content. It is fully hardenable. It makes a very serviceable filet blade as well from my experience.

Stay Sharp.
Randy

 

[jmforge]

duplicate

 

[jmforge]

You are correct, sir. Poor man's L6.:biggrin: IIRC, it is the Uddeholm steel used a lot for big commericial lumber mill bandsaws. The nickel is added to toughen it up. My recollection is that the nickel content may be closer to 2%. The general consensus is that more people would probably use it for hard use straight blades, but it is only available in thin stock. The thickest that I have ever seen is like .103 and I have only seen than once in 5 or 6 years. Typically, it is either the .49 stuff Dan has or maybe as thick as .62.

 

[Mike Davis]

15n20 is a good steel. As Randy stated, it will full harden and should create a great thin knife. Also should have great stain resistance. I see both sides of this conversation. Steel/HT will have a big effect on the performance, but the steel is only as good as the grind..And vice versa. If the HT isn't good, the edge holding and abrasion resistance will suffer, If the grind isn't good....then it doesn't matter what steel it is if it sucks at it's job and no one wants to use it.
Here is the way i see it, A lot of the chef's don't care what the knives are made of, as long as they work well at the specified use. Knifemakers are sticklers for getting the best out of the steel we use, whatever steel that may be. It is a fine line finding the proper balance, That is why we, as makers need the chef's to use and offer us feedback on how our stuff works.

Me personally, i love carbon steels. Hamon's and patina's are a big thing for me. Also they are less complicated to use than the SS counterparts.
To each their own, but i use carbon steels for just about everything i do.


My 2 cents, sorry if it is long and drags on
Mike

 

[Daniel Fairly]

I've been interested in how steels like 15n20 perform on their own.

I am also curious about the long term performance, in theory it should be a good steel. I was impressed by the very minimal testing I have done so far.

Cool looking knives Dan.. If Im not mistaken 15N20 is essentially 1075 steel, with a 1.5% nickel content. It is fully hardenable. It makes a very serviceable filet blade as well from my experience.

Stay Sharp.
Randy

I haven't found an assay of what I'm using but I did find this.

15n20
c .75%
mn .5%
ni 2%
si .25%
fe bal

L-6
c .75%
mn .70%
si .25%
cr .80%
ni 1.5%
mo .30%
fe bal


15n20 is a shallow hardening steel and L-6 is a deep hardening steel.
Both steels are excellent steel for knives and for mixing in damascus, they are different steels and both have there place and uses.

Del

Good idea on the fillet knives, that would be a good use of the ultra thin stock I have, lol either that or Damascus!

 

[Daniel Fairly]

Oh yeah, Thanks for the compliments HHH!

 

[jmforge]

15N20 is a shallow hardening steel as Del said, but the good news is that it is not quite as shallow hardening as typical 1095 or W2. I would guess that at least 80% of the good carbon steel damascus knives out there contain some 15N20.

 

[tk59]

Didn't see that at first. I see the 'lol" but I fail to see the humor in your statement. Isn't an interest in or desire to make kitchen knives what determines if someone "belongs" on a kitchen knife forum? Also, I thought this was the "getting started" section and not the "you don't know diddly so shut up and go back to making your silly bowie knives" section. Did I click the wrong subforum?:O

I actually like talking steel although I have very limited knowledge with regard to forging/HT processes. My comment was a response to the fact the I asked one person about their "ideal" kitchen knife design and your contribution to the conversation was a comment about competition choppers. Your comment had nothing to do with kitchen knives, thus eliciting the "you don't belong here, lol" comment from me.

 

[jmforge]

I was actually commenting about sub part 2, subsection a of your question regarding "toughness" :biggrin:

I actually like talking steel although I have very limited knowledge with regard to forging/HT processes. My comment was a response to the fact the I asked one person about their "ideal" kitchen knife design and your contribution to the conversation was a comment about competition choppers. Your comment had nothing to do with kitchen knives, thus eliciting the "you don't belong here, lol" comment from me.

 

[tk59]

...As a former chef I like a thicker spine for pushing through tougher stuff and he also has thicker stock, I have all kinds of options!

My tougher stuff comment referred to this statement made by Fairly. It was not a question about steel toughness.

 

[jmforge]

Well, then just consider my comment a wild tangent.:wink:

My tougher stuff comment referred to this statement made by Fairly. It was not a question about steel toughness.