"Grumps" wrote in message
...
Hi
I need to drill 1.5 - 2.0mm diameter holes to a depth of about 8mm
in very
soft alloys / lead.
Using a small model maker's drill of unknown rpm only seems to get
to about
2mm easily. The workpiece warms up (actually, quite hot) and it
seems that
drilling stops.
Is there a technique for drilling this type of material? High rpm or
slow?
Ta.



I expect that the flutes of the drill are getting clogged with the
relatively soft swarf. Use a 'pecking' action - drill in a short way,
withdraw to clear the drill flutes then start again. The smaller the
drill the faster you need it to turn. See here for a chart:

http://shopswarf.orcon.net.nz/drillspeed.html

AWEM