tungsten for granite working

["Simon Brown" <moonsong@zzzzzzzzzzzzzzz>]

Walter,

The punches were made specifically for granite working, I asked for soft
shock-proof tungsten inserts 3/8" diameter set into round 1 1/2" bar with a
flat section on each side. The inserts have been sharpened to a chisel
point- maybe it is the tip shape can't handle the pounding.

I made lots of punches last year for our workshop when I didn't have money
for new gear. I got 25 tungsten tips from a quarry trenching machine that
were worn to a bullet point, cut them to about 2" length and welded them to
1 1/2" mild steel rod. The points were indestructible, but the welds could
not withstand the constant hammering. With 12 apprentices in class, each one
fashioning a granodiorite ball, I spent more time in the maintenance
workshop than I did in class. Each punch was re-welded at least 6 times, but
the blunt-nosed tungsten was unaltered.

Since then, I've managed to buy the set of purpose-made punches, and the new
class has started demolishing them. When I return to work tomorrow, I will
check with the manufacturer and report back.

Thanks for the manufacturer tips, Granite City Tool, Bicknell and Trow &
Holden are my next line of inquiry, although I expect the freight costs to
be prohibitive.

Do you use tungsten tips for your limestone work?

Simon