In 6061, 0.75" blind holes, drilled with a No 21 (0.159) bit, cleared out, full of aluminum specific tapping fluid.
10-32 HSS spiral flute tap bought from McMaster: McMaster-Carr
Program using M871, spindle speed of 1000, tapping head settings to Procunier and TPI of 32 for 871. Tap to 0.6 into the hole.
First try, snap on withdrawal. This also happened the last time I tried to do this in brass. Brass? I've tapped many holes before with no problem.
Am I missing something? I did order some of the taps Tormach sells to try. I'd go manual if these little taps had a dimple for a tap guide.
PS, any tips on removing the @#$%ing tap appreciated. I assume the $60 worth of 1" 6061 plate is headed to the recycle bin.