My AC bracket stud snapped the other day so I am in the process of drilling out what's left of the old stud (stuck in the cylinder head). I know the thread size (or whatever you call it), it's 3/8-16, and I have a drill and a tap and die set. My question is what size drill bit should I use for this? And, does anyone know how far I can/should drill into the cylinder head before I ruin it? Thank you in advance for the help.

 

http://www.engineersedge.com/tap_drill_chart.htm

your tap set should have that but since it seems it doesn't print it out and save it

 

Thanks! That's all I needed to know.

 

have you tried an extractor yet? why retap it if you dont have to?

 

have you tried an extractor? if you have you'd know why he's not trying it.

 

Yes i have used extractors many times, that is why I asked.

 

Actually I did use an extractor. Since my cordless drill decided to act up on me I went to Sears to get a new one (with a cord!) and I figured I would try some. It worked fine for me but the stud wasn't very tight, it was just broken off in the cylinder head.

 

I'm glad you decided to give it a try. Alot of time the bolts will be to stubborn to extract, but since you have to drill anyways you might as well try to exract the broken bolt first