"Tom Gardner" wrote in message
. com...
Ok, listen up...you're ALL wrong! I drill up to 300,000 holes a DAY! If a
drill moves, we make crap or something else breaks. If a drill wobbles a
little, it's toast in an hour, and we make crap. We use 4" breaker bars
on chuck keys and blow the teeth off the keys often, we buy 100 keys at a
time...it's worth it. Tighten a chuck in hole one until snug, tighten in
hole two a bit more, tighten in hole three a bit more yet, then tighten in
hole one again just short of busting the teeth off the key. Any procedure
other than this and the drill WILL move on us. Surprisingly, chucks last
5 to 10 years.

You should consider collets instead of chucks if you're drilling 300,000
holes/day. Chucks are a compromise at best.

Regards,

Robin