Annealling 15n20

Aikenn

Active Member
So I am trying to make liner lock. Got a .060x2x4ft 15n20. Now if I was going to make Damascus I would not have a problem. BUT the material is TOO hard to drill HELP. So do I want to try to re temper ?????? Or do I want to do a straight anneal ?????? At what temperature should I attempt to anneal or to re temper????????? Your help is appreciated. RA Kessler Aiken Blades. PPSS went through 1/2 dozen drills
 

Gene Kimmi

KNIFE MAKER
I would assume that the steel you received has not been hardened. I have had some 15N20 that I couldn't drill. I've had good luck just heating it to a low, red heat and air cool. It will then need to be heat treated after drilling.
 

EdCaffreyMS

"The Montana Bladesmith"
15N20 is very horrible for liners.... simply because as it comes, it's "shereodized annealed"....... in other words, half way annealed.

If you have the means, place it in a heat treat oven at 625-650F and soak for 2 hours, then allow it to cool down NATURALLY with/in the oven.

If you use a kitchen type oven do the same, but after two hours, just shut it off, DO NOT OPEN THE DOOR, and go to bed. In the morning is MIGHT be soft enough to drill.

Even with those methods, 15N20 is often hit-n-miss.... it's just a difficult steel to fully anneal.

In the future, I would suggest using another material for liners.... like 410SS or Titanium. Don't be afraid of Titanium..... there is a small learning curve with using it, but once you understand it's working characteristics..... they are absolutely the same each and every time, with each and every piece of Ti..... of course assume its the same alloy (6AL4V is the most common Ti alloy used by knifemakers). That's unlike the 15N20, which always has you guessing, because not two piece are the same. ;)
 

Chris Railey

KNIFE MAKER
I have had 15N20 (supposedly annealed) strip teeth off of my band saw blades more than once. Now whenever I get some 15N20 I have my own little process I go through BEFORE I attempt any work. When ever I have finished forging for the day I will heat it up (red) in my forge and then close the forge doors and turn the gas off. I let it cool inside my forge as slow as possible. Because my forge was already up to temperature when I put the 15N20 in to turn red it takes a very long time to cool. I have not had any issues since I started doing it this way. If you have an oven or kiln I would do it Ed's way.
 
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KenH

Well-Known Member
15N20 can also be drilled with carbide drills same as any other HT'd steel. I don't even try to cut 15N20 with a bandsaw, just use a 4" sidegrinder with cutoff wheel.
 

tkroenlein

Well-Known Member
I agree with all the above. I use abrasive cut offs and carbide drills right off the bat. The good part is that it always heat treats predictably.
 
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