Bolt Removal- Exhaust

[Justinde]

Hi All

As mentioned in an older post, I broke just 1 bolt on the exhaust plate. No matter how much I drill, it just isn't budging. I have HSS drill bits- I went through 4 already. I have started small ( 1/8 inch) and want to work my way up, but the drill just spins. I have tried lubing as I go, but it just spins. This new drill bit that I bought seems to be taking a pounding- it's still sharp- but I'm just not getting anywhere. I have been at it for a few hours now, so does anyone have any tips for me? Any ideas? Anything I should try? Please- I am SOOOOOO FARKING FRUSTRATED!!!:facepalm:

 

[foodfisher]

Re: Bolt Removal- Exhaust

Cobalt bits

 

[Frank Acampora]

Re: Bolt Removal- Exhaust

As stated above, go to the store and buy a cobalt steel bit--NOT the cheap Kobalt brand and not titanium which is only a coating. You want a drill bit that is full cobalt steel.

With stainless, the metal is a bit "gummy" and extremely tough. You must drill slowly so as to not overheat and melt the drill tip. You must also use a "pecking" to generate high pressure. If the bolt has broken flush with the surface of the block, reattach the exhaust plate with about 1/2 of the bolts. Buy a 5/16 diameter roll pin and hammer it into the hole with the broken bolt. Using the roll pin as a guide, drill 3/16. After drilling through the bolt, go another 1/2 inch deep. Do this slowly, constantly clearing aluminum chips otherwise you will gall and snap the drill bit--then you are really screwed.

Try to clear the existing threads or retap. If you retap, go as deep as the tap or the drilled hole will allow and use a longer bolt. Again, go easy on the tap or you will snap it and then you are really------without getting kissed first!