- Joined
- Jan 21, 2005
- Messages
- 63
reprint:
Some time ago I called Paul and asked him how to differentially heat treat a blade at home.This method works for ATS-34, 154-CM and BG-42. Here goes:
A local knife maker guy and Paul worked on this together. The knife maker guy (herein referred to as 'dude' whom put me in contact with Paul) made knives up to 14" long using this method, and then made some swords, so it should work for your ATS-34 project.
So, here's what you do. Take some 3/4" water pipe and grind in a 1/4" split down one side. You will place your knife in the split edge down. On one end of the pipe, braze on a water hose bib. On the other end of the pipe, attach a plug and drill 4 3/16" holes. Finally, lay the rig so that when you turn on the water, it flows downhill.
The idea is that you turn on the water so that it cools the edge. The plug with the holes in it is to restrict the water flow. You want to adjust the water until it is flowing up 1/2" on the blade.
Take 2 rose buds (Oxy/acetylene torches) and heat both sides of the spine.
Heat the back of the blade until it turns just over a dull red color in dark light. if the blade turns bright red, you have gone too far. When parts of the blade start to turn dull red, you are at about 1000 degrees. When the whole blade is a dull red, you are at about 1300 degrees. 1300 degrees is where you are aiming for. You have to go over 1000 degrees to get the spine to drop below 59-58 degrees.
As soon as you get that even dull red, turn off the heat and let the water run until your blade is cool.
The Dude said that originally he and Paul did 10 blades and the first ones didn't get below 55 Rockwell. But with practice they consistently got down to 48-50 Rockwell.
The Dude has since made some swords and differentially heat treated them and they'll whack through 4" saplings with no damage to the edge at all. Pretty cool!
If you want to do this with 440-C, you need to back down on the temperature a bit. You want it at 1100-1150 degrees, not quite at a red color in a dimly lit room.
Paul said that with practice you can get it just right.
I had a fun time talking with Paul about heat treating and his history. He's been doing heat treating since the time when he was IN high school! He knows his stuff! unfortunately I caught him when he was getting ready to turn in for the night. Paul was very pleasant to talk to. I will definitely call him up again!
Some time ago I called Paul and asked him how to differentially heat treat a blade at home.This method works for ATS-34, 154-CM and BG-42. Here goes:
A local knife maker guy and Paul worked on this together. The knife maker guy (herein referred to as 'dude' whom put me in contact with Paul) made knives up to 14" long using this method, and then made some swords, so it should work for your ATS-34 project.
So, here's what you do. Take some 3/4" water pipe and grind in a 1/4" split down one side. You will place your knife in the split edge down. On one end of the pipe, braze on a water hose bib. On the other end of the pipe, attach a plug and drill 4 3/16" holes. Finally, lay the rig so that when you turn on the water, it flows downhill.
The idea is that you turn on the water so that it cools the edge. The plug with the holes in it is to restrict the water flow. You want to adjust the water until it is flowing up 1/2" on the blade.
Take 2 rose buds (Oxy/acetylene torches) and heat both sides of the spine.
Heat the back of the blade until it turns just over a dull red color in dark light. if the blade turns bright red, you have gone too far. When parts of the blade start to turn dull red, you are at about 1000 degrees. When the whole blade is a dull red, you are at about 1300 degrees. 1300 degrees is where you are aiming for. You have to go over 1000 degrees to get the spine to drop below 59-58 degrees.
As soon as you get that even dull red, turn off the heat and let the water run until your blade is cool.
The Dude said that originally he and Paul did 10 blades and the first ones didn't get below 55 Rockwell. But with practice they consistently got down to 48-50 Rockwell.
The Dude has since made some swords and differentially heat treated them and they'll whack through 4" saplings with no damage to the edge at all. Pretty cool!
If you want to do this with 440-C, you need to back down on the temperature a bit. You want it at 1100-1150 degrees, not quite at a red color in a dimly lit room.
Paul said that with practice you can get it just right.
I had a fun time talking with Paul about heat treating and his history. He's been doing heat treating since the time when he was IN high school! He knows his stuff! unfortunately I caught him when he was getting ready to turn in for the night. Paul was very pleasant to talk to. I will definitely call him up again!
