Start with small drill bit

then use bigger size gradually. Do not use big one at first place. Do not use extractor unless you can drill to the size that is close to the bolt size. Extractor is very brittle and hard. If the extractor break, you have no way to get it out. Alternatively, use a allen wrench bit and hammer the bit half way into the drilled hole, then rotate the bit to get the broken bolt out.

所有跟帖： 

• google HEX ALLEN BITS -biglow- ♂ (0 bytes) () 06/23/2009 postreply 14:00:04