[TheForge] drill bit stock

[Keporter at aol.com]

In a message dated 5/31/2005 8:49:43 A.M. Pacific Standard Time,  
erik at methow.com writes:

Does  anyone out there know the type of stock used in the common hardware
store  high speed drill bits for steel.  Do you per chance know the steps
for  annealing them.

Yes,  I ask because I broke a drill bit in a piece  of stock where
welding, reforging, and repositioning was not an  option.  I tried all
the tricks as well as attempting to anneal as I  would a common high
carbon steel and drill it out but it seemed to have  little or no affect.

Thank you,

Roger  Olsen




This sounds like a high speed steel bit. If that's the case, it is not  going 
to anneal enough to do you any good. Can you locate the present hole's  
position accurately enough to drill a smaller hole from the opposite side,  and use 
a center punch to back off the broken drill enough to drill  the out the 
pilot hole completely (drill, punch, drill, punch), then use  a rod to finish 
pounding the broken drill back out of its hole? Otherwise,  you could try finding 
someone who has an EDM for stud removal. You can do  it by hand with a carbon 
arc, but it's a nasty job (wear your  leathers, and cool the work with a water 
stream from time to time, in  order to avoid accidentally welding some of the 
scrap into the  hole).
Mike P.