drill it out

[patriot1]

I have an exhaust bolt that was broken off below the surface on a new project that I recently picked up. I went to drill it out and after breaking a few bits, I realized that someone else had already attempted this and broke a drill bit off in the broken bolt.

What kind of bit do I need to try and drill this out? Any suggestions?

[Pineymudder]

a carbide drill bit will drill through. it has to be solid carbide, not coated. sometimes they have straight flutes. i drill through bearing races and everything with them. works best in drill press at slow speed cause there very brittle.

[El Camexican]

Short of a drill press and proper methods, I’ve used tiny stones on a Dremel to get through the bit and make a hole for another bit or an easy-out. That said, using a machine shop to remove it is the best way by far.

[BarnBoy]

So the best way to do it is set it up in a Electro Arc burn-out machine if you can find someone with the right size collects and tubes. Or, with a mill you could easily drill it out using carbide bits and slow speeds and lots of oil. But all of that requires removing the head and I don't think you can get around that.

[ATC200X4716]

I've drilled out many on a mill either with carbide drills or end mills to nibble away at it. If you get in a jam pm me. You're going to have to take the head off. Carbide drills in a hand drill are a bad idea they are very brittle. You need the rigidness of a milling machine.

[ATC200X4716]

I've drilled out many on a mill either with carbide drills or end mills to nibble away at it. If you get in a jam pm me. You're going to have to take the head off. Carbide drills in a hand drill are a bad idea they are very brittle. You need the rigidness of a milling machine

[patriot1]

Thanks to all: I have contacted the machine shop and they told me to bring it on in. I have an 83 year old neighbor who wants to try and get it first. I'll keep y'all posted. Thanks for the help. I appreciate it.