differential heat treat?

[Jason Fry]

I'm finally around to heat treating a file, a trap spring, and a sawzall blade that I've ground in to blades. Considering the steel is unknown, I was thinking of quenching in oil so as not to break the blades. I was also thinking about edge quenching. Maybe put the edge in the oil for X seconds, then drop the whole thing in? Or would I be better off quenching the whole thing equally then drawing the temper? Any suggestions would be helpful.

 

[siguy]

based on my limited experience, i think it might be easier to whole quench and then draw the temper.

 

[CrowValleyForge]

Experimenting is fun!

But I would, at this stage of the game, like Siguy says, full harden them also, since you don't know what you have, there is no sense in trying to get 'more' out of it.

Think on the lines that the file is 1095 , the trap-spring 5160 or 1085 and the sawsall blade something more like an L6 steel, for my $0.02 cents worth.

It seems that your doing this for fun, so have fun....

And for fun, I would bet the Sawsall blade will harden in room-temp drain-oil,,,,,, the file will need warmer oil (120 or so?) and maybe hotter for the trap-spring, if it dose not, try it/them in water/brine?

Edit: Just for the note to self, spark the steels on a grinder for grins, just for future 'mystery-steel' experiments.

 

[koyote]

It's just pain hard to get a good edge quench with unknown steels and random quenchants. I cracked a lot of blades doing that.

Full quench and a water bath and torch spine draw is how I like it.