Tempering?

[Coomba]

I have a piece of 01 flat stock, that I’m going to grind into a tool, to use to make a keyway in a bushing that I made. I know the procedure for harding, and tempering, but I’m not sure as to how hard I should temper it to?

 

[benmychree]

I have a piece of 01 flat stock, that I’m going to grind into a tool, to use to make a keyway in a bushing that I made. I know the procedure for harding, and tempering, but I’m not sure as to how hard I should temper it to?

TEMPER TO A VERY LIGHT STRAW COLOR AT THE CUTTING EDGE

 

[Ray C]

What is the bushing made of? Will the cutting edge be hitting the bushing with sharp impacts (like a shaper or rotary cutter) or will the keyway be cut with a slow speed hand-operated tool of some sort.

See the graph in this link. If you want impact resistance, temper it at up to temps of 700-800 degrees. If impact resistance is not needed, temper it at low temps of 300 degrees.

https://www.hudsontoolsteel.com/technical-data/steelO1

Ray

 

[Coomba]

What is the bushing made of? Will the cutting edge be hitting the bushing with sharp impacts (like a shaper or rotary cutter) or will the keyway be cut with a slow speed hand-operated tool of some sort.

See the graph in this link. If you want impact resistance, temper it at up to temps of 700-800 degrees. If impact resistance is not needed, temper it at low temps of 300 degrees.

https://www.hudsontoolsteel.com/technical-data/steelO1

Ray

The bushing is made from 1018 and I will be cutting the keyway slowly by hand.
Thank You

 

[Ray C]

The bushing is made from 1018 and I will be cutting the keyway slowly by hand.
Thank You

You're welcome... Heat it till it's red, get the temp up to 1500 which is when a magnet won't stick to it anymore. Dunk it in a small container of oil (for little one-off's like this, I have a mason jar with transmission oil on hand). Just like the instructions I pointed to says, it's best not to quench it until it's cold. Quench it till it's at the limit of being able to touch it (about 150) then, wipe it off and put in toaster oven for 30-60 minutes at 350F.

This tool will be brittle but you will be able to sharpen it like a razor and stay that way. If it were a machine driven tool, you would lean toward a higher tempering temperature to make more flexible at the cost of having an edge that stays sharp.

BTW: If you're using a flame torch, just heat-treat the inch or so for the part that forms the cutting surface.

Take Care...

Ray

 

[Coomba]

You're welcome... Heat it till it's red, get the temp up to 1500 which is when a magnet won't stick to it anymore. Dunk it in a small container of oil (for little one-off's like this, I have a mason jar with transmission oil on hand). Just like the instructions I pointed to says, it's best not to quench it until it's cold. Quench it till it's at the limit of being able to touch it (about 150) then, wipe it off and put in toaster oven for 30-60 minutes at 350F.

This tool will be brittle but you will be able to sharpen it like a razor and stay that way. If it were a machine driven tool, you would lean toward a higher tempering temperature to make more flexible at the cost of having an edge that stays sharp.

BTW: If you're using a flame torch, just heat-treat the inch or so for the part that forms the cutting surface.

Take Care...

Ray

Ray C, just what I needed.

 

[Ray C]

Ray C, just what I needed.

When you quench the part, don't use old motor-oil from gasoline engine. It could ignite.

Good luck and don't let the wife catch you putting oily metal in the toaster oven.


Ray

 

[Kernbigo]

2 hrs. in a kitchen oven on the draw at 500 deg. should get you down to 58-60 rockwell c scale

 

[T Bredehoft]

I find it interesting that on FORGED IN FIRE they don't ever mention/consider tempering/drawing. Just heat and plunge quench. Maybe using a small tube of oil sort of draws the steel a bit instead of a quick quench in a volume of oil.

 

[Kernbigo]

they also don't use a rockwell check, a knife should be around 60 on the c scale