Follow up to some previous inquiries I made recently and more questions.
The tool is a 3/4 x 1/8 x 2" long piece of W-1 water hardening tool steel. It's bevelled along one of the long sides like a short planer knife and it must be razor sharp.
Heated with Prestolite acetylene torch, quenched in water, temepred to light straw at 500º in a toaster oven. [Yes, you can achieve this temperature in a toaster oven. I got an oven thermometer and checked. Leaving it in for 20 min gives a light yellow temper. 40 min. gives a dark straw temper.]
They warped a little after hardening and tempering. Is this just something you have to live with or are there home shop tricks that prevent this? It's not that the warp is bad, but it takes a LOT of grinding / honing to get the blade flat after it's hardened and tempered. I didn't measure the warp, but my guess is that it's less than 0.010" longitudinally.
The 6" belt on my belt sander shined up the bottom nicely, but it certainly doesn't remove metal very fast. The belt was the standard one that came on this Grizzly sander. Are there belts specifically intended for metal grinding that will do a faster job?
Is Water hardening tool steel is more prone to warping than oil hardening?
Observation - It's a lot easier to put a bevel for sharpening on the tool steel with a milling machine before it's hard than grinding the bevel afterwards, even if it has been tempered.
Another observation - you can't "spring" a blade that's been tempered at 500º back to flat. It breaks first. Boy was that interesting. The shop isn't really dim, but when that broke, there was a small flash of light at the break!
Semi-OT - story I heard at college. When they installed the big (4 or 5 stories tall IIRC) Baldwin testing machine in Fritz Laboratory at Lehigh Unversity some time in the 50s /60s they put a piece of steel in it that was at the tolerance of the machine and stretched it till it broke. One of my professors who spoke as though he had been there when the test was done said that it let out a flash of light when it broke and it felt like there was a small earthquake in South Bethlehem. A few windows in nearby homes broke according to the professor.
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