Hi;

Often I need to extract broken bolts / screws and am thinking about
picking up some left handed drill bits. Usually I have to extract
broken steel bolts and screws from aluminum heads and manifolds. Most
often they are broke off clean and need to be drilled. When looking at
drill bits to purchase, I see they are made of HSS, Cobalt and
Titanium. What drill bit material is the best for staying sharp and
long lasting life?

Also, please comment on grabit and other extracting methods. What do
you think is the easiest way to remove a broken bolt?

Thanks for any advice
Pat