In an earlier contribution to this discussion,
Dave wrote:

I have just watched a prog on digital tv (Ideal world) and they were
demonstrating a drill set that can drill through wood, plaster, brick,
concrete, tiles, mild steel, cast iron and bricks. See
www.idealworld.tv
They were saying that they were a tipped drill and the tip was
cryogenically frozen cobalt. Now I have been around drills all my
working life and I can't understand how a drill can keep an edge on
these materials. They did demonstrate what would happen with this
drill, compared to a carbide tipped drill, by pushing it tip first
into a normal carbide grinding wheel. Their drill formed a groove in
the wheel, the carbide tipped drill had its tip ground back.

Has anyone come across them before?

Dave


You often see them demonstrated at Ideal Home exhibitions and Tool Fairs
etc. - where they invariably show them drilling through hardened steel
files, etc. I've got a set and they *do* work - and will go through most
materials. They're quite useful in situations when you're not quite sure
what you're going to encounter - like drilling above windows when you don't
know whether the lintel is concrete or steel. But I wouldn't regard them as
precision devices, and normally prefer the correct drill for the material -
wood bit for wood, HSS for steel, SDS for concrete, etc.
--
Cheers,
Roger
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