ordered some o1

[JamesBBrauer]

I'm all fired up about my little metal order. Have some round drill rods (1/2", 5/8", 3/4") on the way to make some woodworking chisels, and a length of 1/8" x 1" for knives and maybe another drawknife. The junkyard steel projects have been turning out pretty good temper-wise, so I figure it is time to move on to a know metal that I can dial-in better.

My plan is to heat my quench oil to about 180F, get the part to the critical temp (isn't that the same as non-magnetic?) and dunk it. Then bake it for an hour or two at 450F. Depending on how these hold an edge, I may change the bake temp. I've never tried a heated quench, or tempering in an electric oven so if this is a flawed idea, please let me know.

Since I'm far from expert with the hammer, I may try to mill a die for the top side of my chisels and squish them in my little 12-ton press. Seems like it will be easier to get a precise geometry in the milling machine, then imprint that on top of the rod. For the tang, I'm thinking of hammering a shoulder then tapering to a point that fits into the handle.

[dlpierson]

You won't get the most out of O1 that way. It really needs to soak at 1475-1500 for at least 10 minutes before quenching. Quench oil isn't too critical with this steel, medium speed is preferable though. I've used Heatbath AAA at 140F.

Given the above, I've started a series of two hour tempers at 425F and wound up at 440F with good results for me, mostly making kitchen knives.

[j.w.s.]

In the past 13 weeks I've made 47 blades out of O1. Holds an edge real nice once tempered. Now I have 39 weeks to make them all into knives! Have fun, I like working with O1 - no more junkyard steels for me. :)

[kbaknife]

Correct on the soak time. Put simply - VERY simply - "critical temp for a lot of the tool steels is in the range of 1475-1500. O1 should soak at that controlled temp anywhere from 10-20 minutes for complete saturation. To do less is just undercutting the potential of O1.
If you only have the capabilities of getting steel "hot" and then quenching, stick with simpler steels like 1070, 1080, 1084, using the correct speed oil.
Allllllllllllllllllllllllll kinds of folks will say that, "Oh, that just ain't so. I've made tons of blades from O1 by getting them non-magnetic and quenching in french fry oil."
If that's the process you would use, then you would actually end up with a BETTER blade if you used simpler steels.
O1 needs controlled soak time - period.
Non-magnetic is NOT critical temp. It's the IRON in the steel that is going non-magnetic and that is at 1414 degrees. Waaaaaaaaaay short of the temp you need for austenization. Non-magnetic is only an INDICATOR that you are closing in on your target temp.
Even though 5160 and 1084 are entirely different steels and require different austenization temps and times, they will both go non-magnetic at the same temp.

[JamesBBrauer]

Well I reckon I'll have to wire a couple of those left over stove burners into that solid state 220v relay I got at the scrap yard, then run a thermocouple into a lil chip with an Arduino bootloader to control the relay. For a box, I got plenty of Kaowool and Pyrax from making my forge, but I guess I'll have to shell out for a thermocouple and ceramic sheath. Bummer.

Till I get that done, I'm gonna soak the metal by color, and use fry oil controlled with a candy thermometer.

[dlpierson]

If you're going that route you are a good deal of the way to just setting up your forge to be controlled by a thermocouple/PID setup. Stacy Appelt over on Bladeforums has posted quite a bit of instructions on how to do it. Properly done that should easily keep you within 5 degrees F at 1500F.

Caveat: I haven't done this myself. Got most of the pieces but my Evenheat oven doesn't leave me with much motivation to wire the forge up for precise heat control.