Heat Treating O1

[Chewy]

I want to make some file guides out of O1 round. Have a whole lot of drill rod in different diameters. Going to drill a hole in the center and part off. Sandwich the piece between two of them and file away. I have made some before and not heat treated them out of O1 and CRS. Works fine but they ding up and get flat spots from filing. I plan to heat up until they loose the magnetism and quench. That will make them file proof but they will be brittle. I want to temper only to the point that they are not brittle. Their only purpose is to not get filed but I don't want them to shatter rolling off the bench on a cold day. I will do a drop test after I make them. They shouldn't ding or explode.

I know some of you guys do this all the time, I don't. What color should I temper too? I also have a ceramic kiln so I can do this by the numbers too. This is to be a permanent tool in the tool box so I want it to last. Spending the winter making permanent all sorts of work-arounds and wish-list tooling and gadgets.

Thanks in advance. Charles

P.S. the only other option I have on hand is CRS and case hardening, if that would be a better option.

 

[ArmyDoc]

No personal experience, but this is a reference I tucked away to use if and when I get to try it...

https://www.industrialmetalsupply.com/documents/O1%20Tool%20Steel.pdf

 

[f350ca]

New to heat treating as well, just made a gear hob out of O1, hardened it but didn't bother to temper it. Cuts fine, pun intended, I managed to drop it and did break a tooth off the outside row. For file guides I'd leave them hard, even if you drop them I doubt they'd break.

Greg

 

[mikey]

I would go to Amber. That will get you into the high 50's Rockwell C.

 

[benmychree]

I wonder that they would tend to dull your files. I'd suggest temper to light straw color. My info tells me that it should be hardened in oil at 1450-1500 deg. and tempered at 350-500 deg. for a Rc hardness of 62-57, cutting tools 300-350, solid dies and punches 400-450, spring temper750-800

 

[Nutfarmer]

If you are doing it with a torch, heat to cherry red and quench in oil. Then clean with some fine wet dry until you can see bright steel. Next watch the temper color as it is reheated. When it's straw color quench again. If you have a temperature controlled oven follow benmychree recommendations.

 

[T Bredehoft]

Heat to cherry red, drop in oil. clean to bare metal.
Next

REMOVE ALL TRACES OF OIL. ( I use lacquer thinner. )

Oil will appear to turn to straw color, long before it's warm enough to temper the steel.

Once it's clean and dry, wipe the torch across the steel, do not dwell on the steel, until the straw starts to show. Then get the torch away from the steel and let it cool.

 

[cbellanca]

Excellent comments and information on heat treating. What is a file guide and how are they used?

 

[Chewy]

I wondered if straw was right for this. I will try a couple of pieces in straw and amber and see if there is any difference. The pieces are only 3/8" wide so it's not like there is a big investment. I am planning a stepped center hole in each one. Probably 1/4" and 9/64". That is a body size for #10 and the 1/4 countersink will allow an arbor that is slightly long to be used on several thicknesses.

A file guide is a shaped piece of metal that is clamped onto the piece being made. You file and polish to it exactly touches. Tom demonstrates this in the middle of the video below, which reminded me that I wanted to do this. Clickspring also has a swinging file cradle that I want to make. He also shows the file guides in his filing tips video. These are just old ways to make a job simpler and easier.