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Re: What else should I have on hand?

Posted: Tue May 03, 2016 2:47 pm
by superfrog
As nobody mentioned, tapping in aluminium is really easy with a sharp spiral tap in an electric drill/driver with torque control and a reverse gear. Might work with a carbon steel tap too but they are brittle and I generally avoid them in anything that is not very soft or that is worth more than a HSS tap.
(something like this http://www.ebay.co.uk/itm/High-Speed-St ... 1422672920 -- is it ok to post links ?). These are TiN coated, which is not great for Al but works just fine in practice. Brush the tap with a wire brush to remove stuck Al between operations and you should be fine.

Will sound crazy to some, but it works really really well in my experience.

Re: What else should I have on hand?

Posted: Tue May 03, 2016 7:03 pm
by Jimf
Make sure it is a spiral flute type which pushes the chips out of the hole toward the drill side.

Spiral point taps pushes chips forward. If you have a blind hole, you can quickly bottom out the tap and break it.

I find the smaller spiral taps can be fragile so I won't use it with a hand drill. I'm lucky to have a tapmatic and use it on the mill instead.

Be sure to drill the right size pilot hole for the tap. Steel and aluminum are different sizes for the same tap. Always use tapping fluid, I use Tap Magic. Even a drop of oil is better than nothing. Even worse is having to scrap the part if you can't get the broken tap out.

Did I say I hate tapping......