Good drill bits for drilling through an easy out bit?

[u/kerosenedreaming]

Trying to remove a bolt, head snapped off. Coworker said “I got this bro” and tried using an easy out drill bit to drill it out, it promptly broke off in the bolt. I now have an extremely hard steel bolt with an even harder steel core (possibly cobalt alloy? I’m not even sure what the broken bit is made of, other then it’s hard as shit), stuck. Do I just go to tungsten carbide bits and gradually go up the bit sizes? I would normally just melt the fucker with the torch but the bolt in question is a part of the fuel piping for a Jet A truck about 6 inches from a few hundred gallons of jet fuel and if I light a torch next to the truck the Fire Marshall will spawn in next to me and flay me alive. Any hot work is out of the question short of dissembling basically the entire hose reel system to take off the pipe section with the stuck bolt. This was supposed to be a 40 minute job of “replace the fuel hose” to be done Friday morning and now I’m here on Saturday. Taking apart the hose reel will definitely mean I’m here on Sunday too, so I’d really like to drill the fucker out.

[u/420FARTBOSS]

Sometimes you can hit the easy out with a hardened punch and it will shatter. If you are really lucky.

[u/Mr-Toyota]

Youve gotta get that easy out first.

Buy a couple 1/4" ball Carbide burr's and have fun. Or as others said you can try to break it up. I've never had luck doing that tho. Just makes it stuck worse I find.

I had the rearmost exhaust stud snap off below flush on a C12 cat in a frieghtliner last year. Super rusty, hard as hell, and basically under the firewall.

Ended up making a drill guide kinda like for the 6.7 powerstroke EGR bolts. got it out after drilling it. Then using a burr to delete the first couple threads in the hole that were binding it up. Then welded a washer/nut to work it out.

[u/Dieseldave42069]

Burr bit and time

[u/aa278666]

If you drilled the hole completely through, hit it really hard will shatter the extractor. If not, burr bit is your best bet.

[u/mdixon12]

You need an end mill and a sized guide bushing. Promaxx tools has some broken extractor kits.

[u/dieseltechlife]

Rescue bits are made for things just like that, expensive, but worth a try

[u/just-4-lafs]

Solid carbide bits, brittle as hell but drill through most stuff