The Stovebolt Site Forums The Shop Area Engine Shop Broken bolt removal question

I broke the head off one of the two bolts that fastens the rod that goes through the cowl and is bolted w/ the 2 bolts on top of the radiator support on my '46, 1/2 ton. The radiator is out of the truck. I drilled through the bolt and was hoping to use a tap to remove the rest of the broken bolt. Of course I drilled the hole off center. I can see lines inside the bolt indicating the hole is close to the threads. What can I do next?
The only thing I can think of is trying to colapse the bolt with a small cold chisel. The bolt is 3/16th I think. I was going to borrow the right size tap from a machinist friend. I don't have a welder and there's none of the bolt above the hole.
Thanks for any advice.
Jacques

Are you sure about the 3/16? I would suspect 5/16. If you are close to the threads, it might be possible to collapse it. If not, you might want to run a 5/16 bit through it and then tap it to 3/8X16 and drill a 3/8 hole in your bracket.

crenwelge, I'm not sure about the size. I'll measure it. I can borrow a small oxy/acetylene torch if needed to heat it up.
Thanks

Once the hole is off-center, it's nearly impossible to correct the mistake. I'd suggest getting a Dremel tool and some diamond-coated bits, and try to get the hole centered back up. Proceed VERY carefully, and when the hole is close to the minor diameter of the threads, use a tap to chase the remains of the bolt out. If you try to force a bigger drill bit through, it will wipe out the threads, and you'll need to either tap the hole for a bigger size bolt or install a heli-coil. Use a very small abrasive bit at high speed, and a light touch, and you might be able to center the hole up without doing any more damage. Good luck!
Jerry

Thanks, Jerry. I guess an, "Easy-Out" wouldn't work on something like this...? The bolts go through a sheet metal channel shaped radiator support. There's a piece of flat bar, probably spot welded to the inside of the channel, that's the hole that's tapped. The truck isn't restored. It's a repainted original and I'd hate to start butchering it up.
Thanks, Jacques

If a dremel tool isn't handy and you have a hole all the way through a small round file works fairly well to recenter the hole.

Yes, I hadn't thought of that. I was thinking that I could grind down a hacksaw blade to fit the hole but the round file idea and dremel are better ideas.
Thanks, Jacques