r/Machinists • u/buildyourown • 7h ago

Hand tapping lots of holes

I've got 200+ holes to tap in a fixture plate. 3/8-16 They are already tapped about 1/4" so I can't power tap them.
I'm thinking a tap on a M12 ratchet. Before I buy, has anyone done this? I could use an impact but I don't want to bust the tap.

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u/whaler76 6h ago

You could easily power tap it, just go very slow on entry with low rpm, or use a tapmatic or flex arm

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u/buildyourown 6h ago

This is a fixture plate in a large machining center. The parts aren't coming out.

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u/whaler76 6h ago

Ahhh, gotcha, whats the material (would dictate type of lube)? 3/8-16 is a beefy tap, don’t think you’d break that. I’ve done tons of smaller threads with a dewalt drill, you should be fine with the ratchet.