Lathe Cutting Tool for O-ring Grooves (and trepanning)

[Paul Jones]

Thanks PJs. The Rex AAA HSS tool bit is one very tough cookie but can be ground with conventional aluminum oxide wheels on a pedestal grinder using a rough 36/46 grit to take away most of the material. The final grind finish was with 120 grit silicon carbide wheels.

I have another pedestal grinder (toolmaker style) that has 100 and 220 grit diamond wheels but didn't want to waste the diamonds on this tool but may use the 220 grit to product an ultra smooth finish if needed next time. I ground a 10 degree side angle clearances on the sides of tool and added an undercut to the front tip by removing 0.22" for more clearance for the small radius O-ring grooves. In the trepanning work for the T-304 stainless steel plate, I had to run the lathe at 70 RPM and still ran into a lot of chatter and squeak (you know it is bad when even the dogs leave the garage because of the noise - I had my -30dB ear muffs on ). Thanks for the questions, Paul