Trouble with broken bolts. Mag drill available

   / Trouble with broken bolts. Mag drill available #11  
Bolt is M20. I’d take a 3/8” or 7/16” nut and weld the inside of the nut to the broken bolt. If the nut wont accept a socket due to recession in the hole, weld another on top of it. Common practice for a flush break is to start by welding a washer to the broken bolt.
 
   / Trouble with broken bolts. Mag drill available
  • Thread Starter
#12  
It is definitely subflush. I’ve welded nuts and washers to bolts before to remove them, but never subflush broken ones. I might be able to get a nut down into the hole and weld from the inside. Probably need to weld another to it to have enough to grab.

I’m more concerned about welding into the threads somehow. Given it’s on the tractor frame, I don’t want to create a bigger problem than I’ve already caused.

What grade nut would you use to insure best weld? I might have some G8 of that size, but I’m not sure. Otherwise it’s likely just ‘nut bin’ grade.
 
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   / Trouble with broken bolts. Mag drill available #13  
I don't think you'll have any success welding a nut to the harden steel extractor. It'll most likely just break apart. It could be enough to get it out of there.
 
   / Trouble with broken bolts. Mag drill available #14  
Sounds like you have a pretty good section of meat left around the broken extractor. When dealing with broken bolts on Cat exhaust manifolds, I use an 1/8 carbide burr rather than a punch to get the hole started. They are small enough to bore around the outside of your broken extractor too and be able to remove it then. At least that bolt is 20mm. You have some room to work with.
 
   / Trouble with broken bolts. Mag drill available #16  
I have 4 broken bolts on my tractor.

10.9 - 20x90 bolts, broken off about 1/4" below the frame surface.

I drilled one out before and replaced it. Drilling it with a hand drill and time + frustration. But I was able to remove it without anything more than sweat.

I have a compact mag drill now, which can get to 2 of the bolts as is and the other 2 after these are removed and the loader frame is reattached.

So... on to my idiocy and issues.

I drilled out one without incident. Removal was straightforward.

I moved to the second, and put in the same size reverse removal tool, and snapped it off in the hole. So now, I have hardened tool steel inside the center of a hole of the bolt. Admittedly, I cut a corner and used only a 1/4" remover, as it worked on the other 2 bolts I have used. I know I should have taken the time and enlarged the hole for the larger remover, but that is only history and lesson learned.

So now, I need to remove the bolt, with a tool steel center which I cannot drill out with my mag drill, as I only have HSS bits. I cannot find a 3/4" Weldon shank drill bit in Carbide. Annular cutter won't work, I don't believe as it will leave the plug in the hole, thereby, I can't insert the removal tool. HOWEVER, I was wondering whether I could perhaps use an annular cutter and cut completely through the end of the bolt, into the end of the hole within the frame, thereby allowing the plug to be removed. I don't have an annular cutter that small, so 1st, if this is a possibility, I'd need to get a couple of cutters in order to cut deep enough with the shorter cutter, then put on a longer cutter, to allow for the short throw of my compact mag drill. The throw is about 1 1/2" and the bolt begins about 1/4" down in the hole.

Regardless, I need help.

I need either the smallest diameter annular cutter with 3/4" weldon shank, available (small enough to go down the length of a 20mm bolt with room to spare for inaccuracies) or I need a 1/4-1/2" carbide bit on a 3/4" weldon shank with lengths 1" and 2" in order to make it work.

So, if you have a good source for good quality bits like these, I'd appreciate the connection.

Carbide
Weldon shank 3/4"
- 1/4-1/2" dia - 1" and 2" lengths

Weldon shank 3/4"
- Annular cutter (smallest diameter available)
- 1" and perhaps 2 1/2" length cutting depth. ???


Any thoughts would be greatly appreciated.

https://www.csunitec.com/drills/annular-cutters-and-carbide-tipped-hole-saws
 
   / Trouble with broken bolts. Mag drill available
  • Thread Starter
#17  
I would order up a chuck for your drill and get a carbide center cutting end mill it will go down through the easy-out like butter.
https://www.amazon.com/HEAVY-Magnetic-Drill-Weldon-Adapter/dp/B000MQ8R5W
1/2" Diam, 1" LOC, 1/2" Shank Diam, 3" OAL, 1982826 - MSC

I would like to do this, however, the 'throw' of this compact drill is only about 1-1.5". This is the trouble with them, they can cut a hole in about anything and can get in tight places, but they have no ability to cut anything deeper than about 1.5". To get deeper, you have to use a shallower bit/cutter, then change out to a deeper cutter and unhook the drill, slide the cutter over the plug, and then begin again, with the cutter/bit already 'presunk' into the cut.

I love it for most things, and it actually does a pretty good job in this instance. It is the OPERATOR who chose a weak extractor system which is the real problem.

A chuck would take up the throw of the drill and I wouldn't even be able to attach a bit or cutter to it at all.
 
   / Trouble with broken bolts. Mag drill available #18  
I just did four broken bolts on the tow bar swivel plate on my tractor. Use the mig welder with the nut trick. If some of the bolts are too deep below frame surface then take your grinder and remove some of the face material and get closer to the top of the bolt head.. Where your loader frame mounts to will have more then enough material. I have also used the cold chisel ccm trick but gets hard when the bolt is deeply recessed. Good luck; be patient If going with the mig trick. Hold the nut(usually size smaller then bolt) tight to bolt and carefully put the mig wire deep into the hole of the nut. Just tack it to see if it holds. If so fill up the nut hole with weld. Even taken a broken spark plug out of a GMC jimmy head this way.
 
   / Trouble with broken bolts. Mag drill available #19  
I have 4 broken bolts on my tractor.

10.9 - 20x90 bolts, broken off about 1/4" below the frame surface.

I drilled one out before and replaced it. Drilling it with a hand drill and time + frustration. But I was able to remove it without anything more than sweat.

I have a compact mag drill now, which can get to 2 of the bolts as is and the other 2 after these are removed and the loader frame is reattached.

So... on to my idiocy and issues.

I drilled out one without incident. Removal was straightforward.

I moved to the second, and put in the same size reverse removal tool, and snapped it off in the hole. So now, I have hardened tool steel inside the center of a hole of the bolt. Admittedly, I cut a corner and used only a 1/4" remover, as it worked on the other 2 bolts I have used. I know I should have taken the time and enlarged the hole for the larger remover, but that is only history and lesson learned.

So now, I need to remove the bolt, with a tool steel center which I cannot drill out with my mag drill, as I only have HSS bits. I cannot find a 3/4" Weldon shank drill bit in Carbide. Annular cutter won't work, I don't believe as it will leave the plug in the hole, thereby, I can't insert the removal tool. HOWEVER, I was wondering whether I could perhaps use an annular cutter and cut completely through the end of the bolt, into the end of the hole within the frame, thereby allowing the plug to be removed. I don't have an annular cutter that small, so 1st, if this is a possibility, I'd need to get a couple of cutters in order to cut deep enough with the shorter cutter, then put on a longer cutter, to allow for the short throw of my compact mag drill. The throw is about 1 1/2" and the bolt begins about 1/4" down in the hole.

Regardless, I need help.

I need either the smallest diameter annular cutter with 3/4" weldon shank, available (small enough to go down the length of a 20mm bolt with room to spare for inaccuracies) or I need a 1/4-1/2" carbide bit on a 3/4" weldon shank with lengths 1" and 2" in order to make it work.

So, if you have a good source for good quality bits like these, I'd appreciate the connection.

Carbide
Weldon shank 3/4"
- 1/4-1/2" dia - 1" and 2" lengths

Weldon shank 3/4"
- Annular cutter (smallest diameter available)
- 1" and perhaps 2 1/2" length cutting depth. ???


Any thoughts would be greatly appreciated.

v THIS v

Sounds like you have a pretty good section of meat left around the broken extractor. When dealing with broken bolts on Cat exhaust manifolds, I use an 1/8 carbide burr rather than a punch to get the hole started. They are small enough to bore around the outside of your broken extractor too and be able to remove it then. At least that bolt is 20mm. You have some room to work with.
 
   / Trouble with broken bolts. Mag drill available
  • Thread Starter
#20  
I tried with the nut, but a 7/16" nut hole was so small, I couldn't get adequate penetration of the bolt. I think I need to retry after torching the bolt to get some heat into it. I was melting the nut without enough penetration of the bolt to get a strong enough connection to back the bolt out. I also tried with flux core and just couldn't see the tip of the wire well enough to do a good job. I might just try stick next time.

I'm doing this out in my driveway and really need a shop with good lighting, so I can take my time and get into a good position. I am working hard, and getting half-assed results.

I think I will heat the bolt up and try a larger nut. I think I can get a 9/16" on it and still be safe. This has turned into enough of an ordeal that I feel like just taking it to a machine shop and telling them I'll pick it up when they are done.
 

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