Elmax heat treat question

Hktblades

Member
I'm working on a set of kitchen knives in elmax. what would be the ideal hardness to shoot for for maximum edge retention. I've seen similar knives up to 63.5 hrc but have heard that with a good cryo to expect around 62? What recipe would leave me with the ideal microstructure for such a knife? Thanks in advance. Any help would be greatly appreciated.
 

samuraistuart

Well-Known Member
Darrin, I respect your opinion greatly. This one has me baffled. Will you elaborate? Seems like a very good kitchen knife steel in my estimation. I'll know more later this year, as I have a miniature Santoku for the wife in the works (when I have the time between customer orders). Elmax HT by Peter's at 63HRC. Veeeeeery thin edge, it's so thin I thought for sure it would have warped during HT. Came out like a champ. Just needs polishing and a handle.
 

Kevin Cox

Member
I don't hang out here much but I've made a lot of kitchen knives with elmax and I don't see a problem with it. 63/64 is very high for elmax . 61/62 is more reasonable.
Is there better steel than elmax for kitchen knives sure there is and there's a lot worst to .
Elmax at 61/62 will hold its edge very good. I make kitchen and hunting knives with it.

kcknives
 
There is nothing wrong with ELMAX for kitchen knives, it just wouldn't be my first choice. ELMAX's premier quality is toughness which isn't needed in kitchen cutlery. M390/20CV has much better edge holding and is more than tough enough for kitchen duty.
 

samuraistuart

Well-Known Member
I'll open my mouth and remove all doubt. ha ha! 3 things in a good steel/HT.... Hardness, Toughness, and Wear Resistance. I think toughness is often overlooked in the kitchen knife steel and all out wear resistance given too much accolade. Again, I'm just spitballin' here, but the way I see it, ceteris paribus (geometry, good microstructure, limited RA, etc), the paramount factor in a kitchen knife steel is hardness. The harder the better. But it might chip if it gets too hard. That's when toughness plays it's role. Kitchen knife edges often deform because of impacting the cutting board, plate, bone, etc, and don't experience much in the way of abrasion. I think abrasion resistance has limited application in the average kitchen, and becomes more of a liability come sharpening time.

That is why carbon steels are often preferred in the kitchen (not always of course, especially when corrosion resistance is needed or mandated). They can be run very hard, 64HRC+, have toughness out the wazoo, but not as much abrasion resistance. Super Blue comes to mind talking about all this. A great kitchen steel because it has good characteristics. There are indeed abrasive resistant hard carbides (mostly of the WC variety). And while these carbides do add in overall wear resistance, they also help the overall cohesion of the martensite matrix, which in turn makes the steel tougher. Last year after Aldo got Blue 2 in, I hardened a piece of the .140" stock and was simply amazed at how well the coupon refused to break.
 

Hktblades

Member
Thanks to everyone for the replies on this thread. The reasons stated above is why I chose elmax. My first choice was 20cv but at 61-62 it seemed kinda chippy. This is for a high volume ready cooked meals supplier were they cut hundreds of pounds of proteins and veggies a week. I want the knife to be able to take lateral stress relatively well yet still hold an edge and also be able to be resharpened by a novice. Also corrosion resistance is a big deal. Elmax seems to fit perfect for this imo. Elmax seems to be pretty underrated. Ive used almost every pm stainless and I think with the right geometry and ht it's probably my favorite. The problem is I've been using peters. I'm getting an oven tho and need some help getting started with it. Any help would be greatly appreciated
 

Hktblades

Member
There's no problem with peters. that's not what I was saying. The problem is I haven't been doing my own ht and was just asking for a little help. I have read the data sheets. Just looking for something a little more specific. There's absolutely nothing wrong with using peters that's just not the direction I want to go anymore
 
Use the data sheets as a guide, experiment with temps. & times, keep good records/notes, & test your blades. Your tests should be in line with the use of a particular style/type of knife. It is very important to only change one variable at a time so you'll know what made the difference. Have fun and good luck.
 

Andre Grobler

Well-Known Member
I prefer elmax above Rc61 for all purposes... Rc 62+ feels subjectively better to me for the kitchen but if you overdo it then the damage is more... which is normal... the huge big BUT is that the wear resistance at 61+ is so high it is quite a bear to grind cold enough and thin enough for kitchen knives... you require sharp belts when things get thin. I prefer aebl over it and am doing experiments to get elmax up to rc63 to get similar performance to aebl with regards very thin acute edges... M390 is a pleasure above 62... i only temper below 400f 200degc and cryo... if i didnt cryo i would not use either as there are cheaper steels that can be made to do the same in my opinion
 

BossDog

KnifeDogs.com & USAknifemaker.com Owner
Staff member
Elmax and M390 are two of my favorite steels. Both will work well. Elmax loves to perform at HRC 61/62 range and it will take a very thin ground edge. I use M390 for my EDC folders and have for a couple years. I use 61/62HRC for it also. One of the factory metalurgists kept pushing me to go to 62/64 HRC range and test that. I never have but he said it would be nearly as tough (and probably impossible to sharpen)
 
Top