o1 tool steel question

[lunicy]

Don't flame me too bad, I'm self taught:

I know how to machine O1 steel, then heat to critical, then quench in oil to make a bit.

Can I soften (anneal?) it again if I needed to "adjust" some of the machining?

If so, how? Would I heat red hot, or to critical temp and air cool? Some other method?

Thanks

[andremajic]

Try tempilstiks for an accurate temperature instead of using your eye for color perception.
http://www.markingpendepot.com/tempilstikstemperatureindicatormarkersavailableran gesfrom125degfto1600degf.aspx
You can also buy these at welding supply shops.

Temps for annealing and tempering o1 steel:
http://www.simplytoolsteel.com/O-1-tool-steel-data-sheet.html

If you harden the steel, make sure to temper it too, otherwise it will shatter. Tempering can be done over a flame after polishing the metal so you can observe the colors and quenching it again. Refer to the steel specs again to get the correct info.

[DCM]

Try tempilstiks for an accurate temperature instead of using your eye for color perception.
http://www.markingpendepot.com/tempilstikstemperatureindicatormarkersavailableran gesfrom125degfto1600degf.aspx
You can also buy these at welding supply shops.

Temps for annealing and tempering o1 steel:
http://www.simplytoolsteel.com/O-1-tool-steel-data-sheet.html

If you harden the steel, make sure to temper it too, otherwise it will shatter. Tempering can be done over a flame after polishing the metal so you can observe the colors and quenching it again. Refer to the steel specs again to get the correct info.

+1 good advice on annealing at the second website. The key ingredient is to cool SLOOOOOWWLY.

[G. Blessing]

Yes, it can be done, and yes, you heat to critical again, and cool as slow as possible.... Air cooling at room temp will deffinetally soften it down a long ways. Probably as soft as you'd need for most processes, depending on what your doing/what tooling your using-- I'm not a gunsmith, I'm an ex knife maker; but I used O1 exclusevly for the knives I made for several years.


But that won't get it as soft as it was if you started with commercially annealed steel. A true anneal needs a looooong cool down time. as I recall 12 hours was the minimum I was told for an average knife sized steel blank(1/8"x1.5"x~10"). Blacksmiths do it by burying it in a deeeeeep pit of ash from the forge. Some guys use large containers of pellet insulation(vermiculite is one as I recall...been several years since i learned this stuff..) to keep it warm and cool slowly.

But yeah, air cooling at room temp will get you fairly soft, and workable.

Gary

[ipopum]

I have a wood stove so I also have an ash bucket. I have buried red hot metal in the ashes and it was still warm to the touch. May not be very scientific but has worked for what I needed. As I recall it had 6 inches or more of ash all around it.