I've got a question on tapping. I plan on making an alu case for a modding project, and I would need to tap quite a few holes in the alu (I'm planning to build a frame consisting of full square bars of 15mmx15mm, so the holes (M5) would need to be tapped almost all the way through or completely through). anyway, I've got some taps for doing it manually, but surfing on McMaster's website I came across this (link ). I'm not sure the link will work, if it doesn't, go to mcmaster.com and search for item 2748A63. It's a drill tap. Now, my question: can this be used with a power drill (rpm can be adjusted) or is it also for drilling manually?
Don't do it, these are designed for milling machines and similar equipment. Try to find thread rolling screws (trilobular scerws). McMaster has them only to size M2.5, but perhaps these folks can help you http://www.smithfast.com/mscrew.htm .
I've always found a cordless drill with an adjustable clutch chuck works great. This allows you to set a threshold and still quickly tap out the hole.
hmm I've got one of those lying around somewhere, that might just do the trick. I'll give it a try asap, thanks for the suggestion
Me? Hardly ever, since I discovered thread rolling/forming screws. It's so much easier and cleaner. In high vibration applications it even saves the lock washers. The only place where rolled threads are useless are holes for thumb screws. You won't get the screws out without a tool. For deeper holes there are also thread rolling taps. They last a lot longer than the cutting type because they don't rely on sharp edges to cut and have no flutes to weaken the shaft.
