Stainless Steel For Kitchen Knives

[Randy Lucius]

I need to make a couple of Chef's knives. These will be my first. I really like AEB-L but I'm a little concerned about warping especially with thinner blades. Is there a another steel you prefer that isn't as susceptible to warping or should I use AEB-L and just deal with it? Thanks!!

 

[EdCaffreyMS]

I doubt any other SS is going to be less susceptible to warping. Personally, I tend to go with CPM154 for SS kitchen cutlery, but I also have a process that I've developed to deal with warping...... I buy it in 1/8", profile, then heat treat. After heat treat I partially grind it, then surface grind it to the finished thickness I desire (slow and easy). Then finish grind the blade. With really thin kitchen cutlery in SS, it's not uncommon for them to warp just from the heat/pressure of finish grinding..... so taking it SLOW and EASY are musts. I generally use a "backer" of some type when finish grinding very thin blades...... but it's very tricky because my hand isn't always in contact with the blade, and I can't feel heat build up. So it's another of those "Give-N-Take" things.

All that being said, if your familiar with AEB-L, I would encourage using it. Otherwise you have the overall learning curve of another steel to get past.
Most folks don't realize the time and effort it takes to produce a large chef's knife that is also very thin, and balk at the price. That's a big reason that I don't produce a lot of them... and when I do, it's usually in a damascus format, and finished out with clear Gun-Kote.

 

[Gene Kimmi]

I've made a bunch of chef's knives out of .070" AEB-L, and haven't had much trouble with warping. As Ed said, I probably have more warping during grinding than during heat treating. Just keep an eye on it and when it starts to warp one way, grind the other side until it's back straight.

 

[Randy Lucius]

I doubt any other SS is going to be less susceptible to warping. Personally, I tend to go with CPM154 for SS kitchen cutlery, but I also have a process that I've developed to deal with warping...... I buy it in 1/8", profile, then heat treat. After heat treat I partially grind it, then surface grind it to the finished thickness I desire (slow and easy). Then finish grind the blade. With really thin kitchen cutlery in SS, it's not uncommon for them to warp just from the heat/pressure of finish grinding..... so taking it SLOW and EASY are musts. I generally use a "backer" of some type when finish grinding very thin blades...... but it's very tricky because my hand isn't always in contact with the blade, and I can't feel heat build up. So it's another of those "Give-N-Take" things.

All that being said, if your familiar with AEB-L, I would encourage using it. Otherwise you have the overall learning curve of another steel to get past.
Most folks don't realize the time and effort it takes to produce a large chef's knife that is also very thin, and balk at the price. That's a big reason that I don't produce a lot of them... and when I do, it's usually in a damascus format, and finished out with clear Gun-Kote.

Thanks Ed. I really like AEB-L so I'll stick with that and follow your advice. May hit you up with some questions when I get into the project. Thanks again.

 

[J. Doyle]

I doubt any other SS is going to be less susceptible to warping. Personally, I tend to go with CPM154 for SS kitchen cutlery, but I also have a process that I've developed to deal with warping...... I buy it in 1/8", profile, then heat treat. After heat treat I partially grind it, then surface grind it to the finished thickness I desire (slow and easy). Then finish grind the blade. With really thin kitchen cutlery in SS, it's not uncommon for them to warp just from the heat/pressure of finish grinding..... so taking it SLOW and EASY are musts. I generally use a "backer" of some type when finish grinding very thin blades...... but it's very tricky because my hand isn't always in contact with the blade, and I can't feel heat build up. So it's another of those "Give-N-Take" things.

All that being said, if your familiar with AEB-L, I would encourage using it. Otherwise you have the overall learning curve of another steel to get past.
Most folks don't realize the time and effort it takes to produce a large chef's knife that is also very thin, and balk at the price. That's a big reason that I don't produce a lot of them... and when I do, it's usually in a damascus format, and finished out with clear Gun-Kote.

^^^ This all the way.....the steel and advice.

CPM 154 is a pretty great all around stainless.

 

[Randy Lucius]

I've made a bunch of chef's knives out of .070" AEB-L, and haven't had much trouble with warping. As Ed said, I probably have more warping during grinding than during heat treating. Just keep an eye on it and when it starts to warp one way, grind the other side until it's back straight.

Thanks Gene. I'm ordering some AEB-L today.

 

[Randy Lucius]

^^^ This all the way.....the steel and advice.

CPM 154 is a pretty great all around stainless.

Thanks John. I really like CPM 154 too. It's a great steel. I have a hunter model heat treated and ready to finish for myself but I've been busy with customer's knives.

 

[John Wilson]

Historically, I have lots of issues with thin AEBL warping and spend a lot of time straightening after they cool from temper. Steve Miller mentioned that the steel is still relatively soft for some time until it's all the way cool. I decided to test that for myself and he's absolutely right. I usually straighten fillet blades several times during the profiling and drilling stages because .070 bends like a soda can when it's dead soft. This time around I did a fillet and an 8in chef to test Steve's method. I quench between plates, which made both blades absolutely dead flat- then into the dry ice. In my experience, if AEBL is going to warp, it's going to warp in the cryo. This time was no exception.

This is where Steve's advice really paid off. When they came out of temper, I immediately straightened them with my hands wearing welding gloves. I was shocked at how easy it was to do. I'm so used to using my vice and a propane torch that it's become a planned step for me. All this time I was creating an extra step. Just as a sanity check, I went back after they were dead cold and tried to flex them again with my hands. Night and day. They were every bit as stiff as I'd expect heat treated blades to be.

Thanks Steve!!!

 

[Gliden07]

I have some AEL-B .082 coming for Fillet knives (couldn't get the .070 I wanted) gonna be my first delve into SS too! Being this is for fillet knives I hope I can get them to have enough flex? Following thread!

 

[John Wilson]

I have some AEL-B .082 coming for Fillet knives (couldn't get the .070 I wanted) gonna be my first delve into SS too! This is for fillet knives so I hope I can get them to have enough flex? Following thread!

They'll have all the flex you want. Grid them hard and test as you go. You'll get an immediate feedback for how flexible they are based on the grind and cross sectional thickness. Since they're already hard you don't have to worry about hurting it.

 

[J. Doyle]

Historically, I have lots of issues with thin AEBL warping and spend a lot of time straightening after they cool from temper. Steve Miller mentioned that the steel is still relatively soft for some time until it's all the way cool. I decided to test that for myself and he's absolutely right. I usually straighten fillet blades several times during the profiling and drilling stages because .070 bends like a soda can when it's dead soft. This time around I did a fillet and an 8in chef to test Steve's method. I quench between plates, which made both blades absolutely dead flat- then into the dry ice. In my experience, if AEBL is going to warp, it's going to warp in the cryo. This time was no exception.

This is where Steve's advice really paid off. When they came out of temper, I immediately straightened them with my hands wearing welding gloves. I was shocked at how easy it was to do. I'm so used to using my vice and a propane torch that it's become a planned step for me. All this time I was creating an extra step. Just as a sanity check, I went back after they were dead cold and tried to flex them again with my hands. Night and day. They were every bit as stiff as I'd expect heat treated blades to be.

Thanks Steve!!!

John just to be clear....what are the steps in your process regarding quench, cryo and temper?

Just asking about order of operation and not specific temps.

 

[John Wilson]

John just to be clear....what are the steps in your process regarding quench, cryo and temper?

Just asking about order of operation and not specific temps.

I heat treat the profiled blank, quench between plates. Then when I can hold it comfortably by hand I put it in the freezer to bring the temp down continuously. After about 30 minutes or so (cold to the touch) I put it in the dry ice / alcohol slurry. It stays in the cryo usually overnight and then goes into the temper oven.

I added the freezer step as a mitigation to warping. Early on, I'd put the blades in the cryo at room temp (which is about 95 degrees in Florida) and I got a lot of warping. I added the freezer step to bring the temperature down to reduce the thermal delta hoping it would help, and it does on thicker blades. The blades that are thin for their length seem intent on warping a little no matter what I do.

 

[J. Doyle]

I heat treat the profiled blank, quench between plates. Then when I can hold it comfortably by hand I put it in the freezer to bring the temp down continuously. After about 30 minutes or so (cold to the touch) I put it in the dry ice / alcohol slurry. It stays in the cryo usually overnight and then goes into the temper oven.

I added the freezer step as a mitigation to warping. Early on, I'd put the blades in the cryo at room temp (which is about 95 degrees in Florida) and I got a lot of warping. I added the freezer step to bring the temperature down to reduce the thermal delta hoping it would help, and it does on thicker blades. The blades that are thin for their length seem intent on warping a little no matter what I do.

Thanks John. I was thinking that was the order but just wanted to be sure.