On 5/3/2011 4:52 PM, John Doe wrote:
Lots of questions about tapping this.

2017 aluminum collar/rod
64 mm length (about 1" will be used)
22 mm outer diameter
8 mm inner diameter

The rod will be pushed into the hub of the skate wheel and the
assembly will screw onto the arbor of the cordless drill. That
looks like a more simple and efficient way to mount the wheel.

http://www.flickr.com/photos/27532210@N04/
http://www.flickr.com/photos/27532210 N04/ (sign removed)

I need to thread the 2017 aluminum collar described above.

For what it's worth, I have this little tap and die set.
http://www.lowes.com/pd_232550-1083-...ductId=1065037

Is the collar's 8mm inner diameter appropriate for 3/8 inch 24
thread?

Otherwise, what size drill bit?

Can the inner diameter be accurately enlarged simply by drilling
into the 8mm collar hole? There was a recent thread about that, I
think, but the discussion was not perfectly clear to me.

Searched Amazon for "3/8 24 thread tap".
(Other online merchant reference links are invited.)

Union Butterfield okay?

The thread length will be 1", or greater if doing the whole 64 mm
collar at one time (I guess not).

The tap finish, like black oxide, makes no difference for tapping
into 2017 aluminum?

A tapered tap is unnecessary since it is a long hole? The main
concern is that the collar/wheel assembly is secure and centered
on the drill arbor, so that the wheel spins without bouncing. A
very close collar& arbor fit would be nice.

Is "H4" better than "H2" for this?

Thanks.




Handbook says that for a class 3 thread, your minor diameter should be
..330 - .337 , so no, I wouldn't attempt tapping it without enlarging it..
I would just take the hole out to size with a reamer and tap it. Making
sure to put a lead in chamfer on the part so the tap doesn't end up
chipping.

Or you could try a drill, drills tend to not make great reamers, but you
might get lucky in aluminium.