Simple job, dumb machinist.....

by Andy
(Deer Park, WI)

I bought a dozen new turning/facing bits on Ebay, dirt cheap. 5/8" square shank, I need 1/2" square. I figured it was an easy job to cut them. I destroyed 3 end mills and finally figured out I need help. I'm a rookie and the handbook seems to be in a different language.

The bits are marked Swiss Kx and 1F1 if that means something to someone. Please help me with the proper tool, speed, RPM and cut depth to remove 1/8" from two sides. Thanks, Andy

You can purchase American Made tool bits here.

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Jan 26, 2013
Looks like you will have to grind them
by: Patrick


The tool bits are hardened to about RC 63-65 and the end mills are hardened to about the same hardness. Since the hardness is about the same, the end mills wont cut the tool bits.

In order to cut the tool bits, you would need to have a cutting tool made out of something significantly higher in hardness, like RC 70, to cut them. That would be considered "hard machining". Hard machining can cut materials up to about RC 58 or 59 and would require special fixturing.

It looks like the only practical solution is to grind them. The grinding wheel particles are about RC 80. Grinding will work, but it will definitely take some time to remove 1/8" of stock. If you have a surface grinder available, use a 5SG60-GVSP grinding wheel and coolant.

Good luck.

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