o1 heat treat at at home - questions

S

solvetek@yahoo.com

Joined
Oct 27, 2007
Messages
6
I am making a wood carving knife for myself and this is my first homemade knife.
I want a thin blade and will use 1/16 thick o1.
I know that 10x is better than o1 for beginners but I got a very good deal on the o1 and could not find 10x in 1/16.
The blade geometry is as follows: 1/16 thick, 1.5 inches long, 1/3 inch wide.
Heat treat process
1) heat with two propane torches, one on each side of the blade.
2) test with magnet until the blade is non-magnetic.
3) Once the blade is non-magnetic I will soak or continue to heat for 3 minutes trying to keep the same color.
4) after the 3 minute soak dunk straight into a glass of canola oil heated to 125 degrees.
5) after it cools bake in oven at 400 degrees for one hour
question:
1) should I put a dull edge on the blade before I heat treat, I have read that the blade edge should not be two thin?
2) does the heat treat process I am using sound reasonable?
 
If you have a few fireplace bricks (hard or soft, soft is better) to make a small chamber you would be better off. So do you want to point the flames at the knife and move the blade back and forth to heat it? Once the blade is non magnetic, you should only continue to heat it long enough to change colour slightly but really not more than a minute unless you cant keep the colour steady. Use much more than a glass of oil, a gallon would be better, I know it sounds overkill for such a small blade but you would be surprised how quickly the oil can heat up. With such a small, thin blade you might want to wait until after you heat treat to put the bevel on it at all. Are you using a file or power tools?
 
I have a video that covers the heat-treatment process for O1 here:

[video=youtube;8bunCG6W6dA]https://www.youtube.com/watch?v=8bunCG6W6dA[/video]

You need to go hotter than non-magnetic, so I don't recommend using the magnet as anything other than a reference. I prefer to use the color of the steel instead. The color should be dull cherry red as seen in relatively dim light, no sunlight or bright indoor lights as they will hide the color of the steel!

As said above, using a small forge like a coffecan forge or 2 brick forge will make life a lot easier.
 
All,

Thanks for the info!

aarongough,

I watched your video and noticed that you do not soak the blade as some others do. I would like to produce a blade that will take a fine edge and have a rockwell of 60 - 62. Will I be able to achieve that without soaking the blade with 01?
 
solvetek@yahoo.com said:
All,

Thanks for the info!

aarongough,

I watched your video and noticed that you do not soak the blade as some others do. I would like to produce a blade that will take a fine edge and have a rockwell of 60 - 62. Will I be able to achieve that without soaking the blade with 01?
Click to expand...

When heat-treating a blade without close temperature controls overheating the blade can be a problem, especially at the edge where the steel will heat up quickest. I do soak my blades when heat-treating this way, but only for a short period of time to help minimize the risk of overheating.

You will definitely be able to produce a blade that will take and hold a fine edge, though I doubt you will achieve 62HRC, the blades that I have tested after heat-treating this way came out around 59HRC. Heat-treating by eye like this is an art that requires practice. You will likely get decent results on your first shot if you're careful. If you want maximum performance from any steel then a kiln is usually the best way to get that.
 
I have done 1,5" 3mm carving blades with the same HT as in the video and 4 years later i still have not found a flaw with them. A trick on super small blades is to heat the tang and back of the blade and let the heat spread. If I were to do it again i would put a small steel pipe in the forge and stick the blade in to the tube to make the heat more even and "slow".

The pipe trick is from Tubal Cains book on HT.
 
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