Re: copper washers

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Ian Macky <ian.macky-at-oracle-dot-com> 

 > Please make sure that the sheet is VERY well anchored, or it can get away
 > from you and shred your fingers.  Learned the hard way.

best never to drill big holes in sheet metal with a twist bit:
it digs in, grabs, spins the sheet like a blade, lops off your
fingers, etc.

use a step bit.  the single-flute design is safe, won't grab,
and you can drill large (1" etc) holes.  not that expensive,
worth the price 1000x over.

yes, always clamp the sheet, no matter what you're drilling with.

MSC has nice copper washers, but min quantity is usually box of 100.

a round panel punch meant for mild steel might make decent washers,
but you'd have to flatten them when done as they'd be potato-chipped.