wrote:
I've got blisters on my hands from taping 20 holes manually and I have
hundreds left to go!
What machine or tools do I need to tap 5/16th-18 holes in aluminum? I
am using T slotted 1.5" square tubular aluminum for a lot of projects,
ranging from a workshed to a photobooth to a workbench and having to
manually tap the ends of this metal is going to kill me! I'm
specifically using http://www.8020.net/T-Slot-1.asp this stuff. I
bought two specialty taps that are a combination drill/tap bit from
www.mcmaster.com part # 2748A43 At $20 each they are pricy and I've
already busted them both after only about 6 holes each with a hand
drill.

Any help please?

Dewalt cordless drill. With reverse.

There are tapping machines out there, that look like an air drill on a
swingarm, for production use.

A tapping head on a drill press, can be got cheap if you have time to
shop ebay, or less cheap if needed immediately.

Cheers
Trevor Jones