Well, Google so far has NOT been my friend.
With a HSS 2-56 tap broken off in a lump of bronze I did my search -
found reference to "jewellers' screw remover, a white paste". Looked all
over the place in jewellers' webpages and couldn't find a thing.
There was recent reference here to the use of alum (septic pencil), but I
believe that was for use for a tap snapped off in aluminum.
I could move the hole over and retap, but it would throw off the symmetry
of the piece - however if the worst comes to the worst.
Help!
Mike in BC