Head Broke Off Bolt...Please Help!!

[Chilly807]

Probably what happened is that as the drill bit broke through the end of the bolt it grabbed hard and the torque snapped the bit. That's bad news for two reasons, first of all the bit is going to be a b**** to back out, secondly if you hammer too hard on it you may crack or break the casing behind.

My first question is, how critical is that one bolt to the operation of the corn head? If nothing is compromised or leaking, leave it alone until the whole thing has to come apart.

You may be able to take a Dremel with a small stone and grind away enough of the bit to get the easy-out in there, but they've been known to break off too. Don't ask me how I know this..

If it's in a location that will stand heat, heating the drill bit cherry red with a torch will take the temper out of it, maybe enough to drill it, but that's a tough job even in a drill press.

If it were me, I'd try sticking a welding rod to it, like the guys said the weld won't stick to cast well. A MIG will work too, if you can weld something to the end of the drill bit or even better to the bolt shank it MAY back out. The drill bit will for sure if what you weld to it will stand the torque to break it loose.

Only other solution is a machine shop with EDM capability to burn the bit and bolt out. Once the bit is out, if your first hole is well centered you can slowly increase drill size until you can pick the threads out or run a bottom tap in the hole.

Good luck,

Chilly

 

[dqdave1]

first; if you use a punch on drill bit; wear safety glasses and protect bare skin as shapnel can come off that bit as it breaks. If you get it out; invest in left handed drill bits and use them first as as they bite, they will back out bolt; hopefully. If you use an easy out and it breaks; you are right back in situation you are in now.

 

[Prodirt6000]

Chilly thanks for all the advise.

I thought the punch idea was a good idea but I do worry about damaging the material behind it.

The bolt is one of the two bolts for one of the scraper plates under the corn head. That plate needs to be there...I could try making something else to hold that plate on, but would really rather have the bolt out and new one in.

 

[Prodirt6000]

Dave I actually did break an EZ out in the hole. I failed to mention that earlier only because I did have a drill bit that drilled right through it. I was very surprised. If that never happened, I would have had to go back to using a small drill bit to make a new pilot hole and I wouldnt be in this situation.

 

[Travelover]

I have backed bolts out by using a small punch to turn the bolt as I hammered. You need to hit it tangentially on the face.

If you can get the broken drill bit out, you can enlarge the hole until the bolt is just a thin piece, then peel it out with a small punch.

 

[radioman]

Is the bolt placement critical ? Sometimes when you get yourself in a hole like that (pun intended ) you just gotta grin and bear it and drill a new hole off to the side. If bolt placement is critical- think twice about using the welding with 7018 as the backup plan. If you use a punch to try to shatter the drill bit, you might find yourself with nothing to weld onto. plan ahead on whats "ifs" first before yiou start swinging that hammer. Don't ask em how I know-

 

[redharley]

I think we are missing some of the story,You mention that you did break an easy out off,so now I have to think that bolt is fast, not just with the head broke off. Am I right in this thinking?

 

[Chilly807]

I have backed bolts out by using a small punch to turn the bolt as I hammered. You need to hit it tangentially on the face.

If you can get the broken drill bit out, you can enlarge the hole until the bolt is just a thin piece, then peel it out with a small punch.

Exactly... a center punch will sometimes turn the old bolt out, and a cape chisel (rounded tip) works well for getting the thin shell of the bolt out, it'll actually collapse it inward on itself with a few taps once you have it drilled thin enough.

I've not personally tried the welder trick, but I think if you can get an arc started,then deliberately stick the rod and turn the welder off, you might get enough bite to turn the drill bit out. Or maybe clamp a set of vise-grips on the rod and give it a smack with a hammer, use it like a slide hammer. Once the bit is out 90% of your problems are over. Any body else have any thoughts on this?

Chilly

 

[CurlyDave]

Before you do anything, try heating it and touching it with a candle to get molten wax to wick down the threads of the bolt. This makes the bolt a lot easier to turn...

 

[Prodirt6000]

Yeah I guess the reason why I didnt mention the EZ out was because I could easily drill through it. The bit broke off inside of it after going completely through it. I should have mentioned that though.

And the bolt hole is part of a framing piece on the bottom side of a 6 row corn head. This particular bolt holds one of the scraper plates on.