Removing a broken bolt the easy way

[Lavoy]

I know I have talked about it on here in the past, but wanted to show some pics of how to do it, that might explain it better.

First a pic of the broken off bolt. This one is the trunnion plate mounting bolt on a 440 crawler.



Weld a washer to the bolt.



Then weld a nut to the washer, let cool, and remove the offending bolt.




They don't always go this slick, but it gets the lion's share of them out quickly and easily.
This process can be adapted to many different positions and types of broken off bolt, but this is the basic process.
Lavoy

[gus]

That has been my first option too. Works great.

A second and not as easy option, when you can't or don't have enough bolt to weld, is left hand drill bits. Many times the heat from drilling and the drill friction will turn out broken bolts.

[JD440ICD2006]

I third this idea.
Had a 3 point utility blade that was held by a one inch bolt. My buddy slammed a large rock and broke the bolt.
It left just enough bolt "above ground" to piss you off. LOL
We took a one inch nut and literally melted it to the bolt with a Lincoln AC/DC tombstone. Used - DC @ 105 amps, 3/16" 7016 rod.
It took a pry bar on the wrench to get it out but the weld never cracked.
We replaced it with a grade 8 bolt so next time something else will likely give.

[shinnery]

Another thing I have been told to try in a case like this is drill a hole in the broken bolt and fill it full of weld before you weld the nut on. Supposedly the weld in the hole will shrink the bolt when it cools and allow it to come out easier.
Bryce

[Lavoy]

Correct, I have used that more times than I can count. If this bolt had not come out after a couple tries, drilling the center out was the next option.
Lavoy

[gus]

Another thing I have been told to try in a case like this is drill a hole in the broken bolt and fill it full of weld before you weld the nut on. Supposedly the weld in the hole will shrink the bolt when it cools and allow it to come out easier.
Bryce

Works on bearings too.

[tjdub]

iterally melted it to the bolt with a Lincoln AC/DC tombstone.

Haha. I've never heard that term before, but I instantly knew what you were referring to. My neighbor has one of those old stick welders. Never realized what it reminded me of until now

[LarryD]

Being a machinist/welder for 25 years I have done this more times than I have fingers and toes and it is the best method of removal if you can get to it. Broken dowel pins can be removed in a similar fashion by welding a stud to the broken dowel then use a slide hammer to pull the broken dowel out. The heat and impact from slide hammer will usually free it up enough to get it out.

[Lavoy]

Heat and vibration are far and away the the number one thing to remove stuck and rusted bolts.
Lavoy

[Lu47Dan]

Another thing I have been told to try in a case like this is drill a hole in the broken bolt and fill it full of weld before you weld the nut on. Supposedly the weld in the hole will shrink the bolt when it cools and allow it to come out easier.
Bryce

Works on bearings too.

Gus , a friend of mine brought me a housing with a bearing race frozen into the bore. He had tried punching it out to no avail, he wanted me to machine it out, I decided to run a couple of stringers on the bearing surface to shrink it first to see if it would come out. Lots of smoke and fire after the first pass but after it cooled the race fell out of the housing with just a couple of taps. I called him to come and get it the same day he dropped it off.
Once he got the manual on the machine, so he could assemble the new parts into the housing he called me again on how to freeze the bearing race a it said in the manual. I told him to put it into his freezer and leave it overnight. He called the next day and said it worked well.
Lavoy, I usually do not use a washer when doing that.
One warning, if you have a lot of stuck bolts to do buy UNPLATED BARE nuts and washers. Cad-plating when burnt is not good to breath.
Dan.

[Lavoy]

I used not use washers, still don't all the time, but when the bolt is closer to flush, I have found you can get a little better bead on the bolt than I can when welding down through the nut, at least with a wire welder. If I was using stick, maybe not as big of a deal.
Lavoy

[Scottyb]

I have a broken bolt problem. On my 450b loader the top side frame to clutch housing bolt (3/4 x 3-3/4) is broken off an inch or two inside the mounting hole. Can that bolt be drilled? Is their another way?
Thanks,
Scott

[Lavoy]

A little hard to do if you have to do it horizontally, but you can reach up in there and weld your way back flush so you can weld a nut on there. The main thing you have to worry about is not letting the arc get directed towards the side of the hole at all, or you will be welding your "plug" to the side of the hole, then you have a mess.
If you can get the hole vertical, then it is much easier. Keep the gun perfectly vertical and centered, and just let it burn until you fill the hole to the top with the weld. The molten puddle will flow out to the edge of the hole, but as long as you never direct the arc to the side of the hole, you are not actually welding it.
Same story with a stick welder, maybe even a little easier to do.
Lavoy

[gus]

One more trick. When you are trying to drill something HARD, get a maconry bit (carbide) and resharpen it like a regular drill bit. It will drill most anything. They are brittle, but also cheap.

I've drilled out roll pins with them. Works good on hard bolts too.

[Ray]

I have welded onto bolts that are broken inside the hole as Lavoy described but I put a piece of copper tube into the hole first to make sure that I don't weld to the side of the hole.