"Charles Morrill" wrote in message
news:200503181931191575%deichles@yahoocom...
Is it possible to drill a hole in High Speed Steel? What sort of
drill bit do you need? I need to drill a 4 mm hole through some 4
mm
material.

Thanks, Charles


Charles,

If it is a 'one off' I'd use carborundum dust or preferably diamond
slurry. 'Valve grinding paste' from a car accessories shop will do.

Make a 4mm copper 'drill' - just a flat ended piece of rod. Mount it
in the drillpress, and build up a dam where you want the hole using
plasticene or putty. Fill the dam with a mixture of oil and the
abrasive, and bring the 'drill' down at about 100 rpm keeping gentle
pressure on the work. Every now and then raise the drill and lower it
to keep fresh abrasive at the cutting face.

You'll be surprised how quickly it works. Same technique can be used
to drill glass.

AWEM