View Single Post
  #3   Report Post  
Posted to rec.crafts.metalworking
Spehro Pefhany Spehro Pefhany is offline
external usenet poster
 
Posts: 1,475
Default How bad is 0-80 to tap in aluminum?

On Wed, 14 Mar 2012 14:47:02 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Spehro Pefhany fired this volley in
:

Looking at using some relatively small screws tapped into (probably)
6061 aluminum. Through holes, maybe 0.08" of material. Is it insanity
to think about using a cordless hand drill and run them right through
without backing off (assuming a good quality coated tap and aluminum
cutting fluid)?


Maybe with a 65% thread clearance hole, but I wouldn't. Hell! 0-80 is
small enough to break just by thinking about tilting it off-axis. How
would you get it straight with a hand-held drill?

What's the matter with chucking it up in a finger vise, and doing it that
way? At least, then you could use a drill press to get your initial
alignment.

LLoyd


Mostly to save time, and because I've gotten away with it on larger
taps, but your point is well taken.. much off-axis force is going to
be fatal, and there won't be much 'feel' with a heavy drill.