Fillet knife hardness

[skillgannon]

I am making my first fillet knife for a guy at work. I used .095 stock from Aldo and quenched in canola. I tempered at 345 in my wife's convection oven. Will that be to hard?

 

[JTknives]

I am making my first fillet knife for a guy at work. I used .095 stock from Aldo and quenched in canola. I tempered at 345 in my wife's convection oven. Will that be to hard?

Did you use mystery steel?

 

[skillgannon]

Did you use mystery steel?

Sorry I totally forgot to list the steel. It's 15N20. 2 or 3 (I forget) normalizing cycles and a 3 min soak. 345 temper because the convection settings on our oven do some wierd math. It's a FFG 8" blade with distle taper the full length.

 

[JTknives]

You most likely will be just fine. It all depends on how well you hit the sweet spot during hardening. 15n20 will hit 66rc+ if not allowed to over heat. This requires a heat treat oven and testing to find the "perfect" temp. But generally speaking I would expect a normal Heat treat to hit 64-65rc easily if done right. I find a 300° temper with a 66RC blade will drop it to 63RC. After that it seams like every increase in temp by 25° will drop 1RC. So if I had to guess I would say you are in the range of 60-61. Which is more then fine for a fillet knife.

15n20 is very tough and a lovely steel to work with. It can take a very thin edge and still handle some crazy abuse. I would like to see your blade. When I make fillet knives from 15n20 I also do a full flat grind but I take the bevels down to a zero thickness edge. Then a light zip across a fine belt with the edge down to create a burr. After a quick strop on leather or a buffing wheel it's laser sharp.

 

[skillgannon]

You most likely will be just fine. It all depends on how well you hit the sweet spot during hardening. 15n20 will hit 66rc+ if not allowed to over heat. This requires a heat treat oven and testing to find the "perfect" temp. But generally speaking I would expect a normal Heat treat to hit 64-65rc easily if done right. I find a 300° temper with a 66RC blade will drop it to 63RC. After that it seams like every increase in temp by 25° will drop 1RC. So if I had to guess I would say you are in the range of 60-61. Which is more then fine for a fillet knife.

15n20 is very tough and a lovely steel to work with. It can take a very thin edge and still handle some crazy abuse. I would like to see your blade. When I make fillet knives from 15n20 I also do a full flat grind but I take the bevels down to a zero thickness edge. Then a light zip across a fine belt with the edge down to create a burr. After a quick strop on leather or a buffing wheel it's laser sharp.

Thanks. I will post it later after I get the hand sanding done. Right now I gotta go deer hunting.

I quenched them all with just profiling. I am adding the bevels after heat treatment. The .095 stock was awsome but the .065 looks like bacon. Any ideas what might cause that?

 

[JTknives]

That's really weird, I have never had 15n20 go bacon edge on me. But that being said the thinnest I have quenched was .072