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John John is offline
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Default Drilling and tapping 200+ 3/8" holes in 3/4" aluminum


Great. I am thinking, use a spotting drill, and drill a full diameter
hole that is perhaps 1/8" deep. That would provide good centering.




If you use 60 degree center drill and go to a depth of half the hole
diameter of the 3/8 thread diameter the finished hole will have a nice
chamfer on it with no need for any deburring.

John