You guys are savages!!!!:notworthy I can see torching 1" bolts but would never have the confidence to go at a 7/16"... Once we had the shaft of the main pulley on a JD CT322 snap off flush... This shaft is press fit into a threaded sleeve which we couldn't get out. After destroying well over 100.00 worth of drill bits our mechanic used machinists burrs in a pneumatic drill and ground the center out till all that was left was threads which he then picked out, chased the hole with a tap and we were back in business... you just can't teach the skills that you REAL mechanics have!:notworthy
-
Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!
Broken bolts
- Thread starter RobVG
- Start date
Diagonal Brace
Well-Known Member
Ridgid tool makes a good line of straight flute extractors which dont tend to wedge in the hole. They have a sliding nut so they can be driven deeper into the offending culprit. They were and maybe still are sold by Snap on.
Scrub Puller
Senior Member
Yair . . . As I have mentioned on here before I have removed probably hundreds of flush broken studs right down to quarter with the weld on washer then weld on nut technique . . . TIG is best with 316 filler rod
It works best on blind holes as, probably part of the reason a bolt broke with a through hole was the thread locking up from corrosion as the exposed section tried to backout through the thread.
When that happens you pretty much are stuffed and will have to drill it and blow it out as several posters have described. I found it went better with two oxy sets, one with a largish tip to get the heat into the bolt and the other with the smallest tip capable of blowing through . . . you can usualy see the threads showing black as you 'wash' away the metal.
Another trick if you can get at the end of the broken stud is to drill it and then hit with about 600 amps with a dead short from a Hobart or some such welder . . . you can get the whole stud glowing cherry red in a few seconds and then blow it with the torch.
This is the best method if you have the gear as the surrounding metal stays relitivaly cool which gives a bit of leeway with the torch.
Cheers.
It works best on blind holes as, probably part of the reason a bolt broke with a through hole was the thread locking up from corrosion as the exposed section tried to backout through the thread.
When that happens you pretty much are stuffed and will have to drill it and blow it out as several posters have described. I found it went better with two oxy sets, one with a largish tip to get the heat into the bolt and the other with the smallest tip capable of blowing through . . . you can usualy see the threads showing black as you 'wash' away the metal.
Another trick if you can get at the end of the broken stud is to drill it and then hit with about 600 amps with a dead short from a Hobart or some such welder . . . you can get the whole stud glowing cherry red in a few seconds and then blow it with the torch.
This is the best method if you have the gear as the surrounding metal stays relitivaly cool which gives a bit of leeway with the torch.
Cheers.
if you have a twisted off steel bolt in a cast iron block or manifold. you can't torch cut cast iron (or stainless) like you can steel so if you heat it up red real carefull then touch the o2 it is like magic, although the melting temp of steel is 2750 and cast is like 2300 the steel bolt just runs out of the cast iron threads like water. when i did maintence at a steel mill they had big flanges on the trunions on the ladel where the J hooks from the crane latched onto it to pick it up. if the operator was a little to far to one side the J-hooks would pick up on the flange and shear all the bolts off in the blink of an eye. it was like a 3 time a week thing to have to go down and work on a 1500* ladel trying to get those stupid bolts out. mag base drill press and drill untill you work hardend the bolt or twised off an e-z out then i would have to go after it with a carbon burr. they would never let me use a torch because the ladel was so expensive.
still learn'n
Senior Member
My little experience with cutting out bushings and bolts with torch I use a gouging tip on torch and it doesnt seem like it don't cut into the metal surrounding the bolt or bushing as easy as a regular cutting tip! Jerry
3rdgendslmech
Well-Known Member
Fellas I feel your pain. At least for the majority of you guys your equipment isn't in the worst environment imaginable. Basically everything I work on is around SALT. Yea....salt from your everyday Morton table salt, to solar salt they spread on your roads in the winter. Working on that equipment is no fun at all. But, here's a few little tricks I found out real quick to deal with broken bolts, studs, and rounded off heads.
1. If the bolt is big enough and not blind holes. Drill a decent size hole through the center of it. This acts as a relief for the melted bolt to run out of. Now remember, yes its a torch, but be very surgical and delicate with it. You can actually melt away at the bolt til you start seeing threads appear of whatever it is you are working on.
2. Blind holes are a little trickier to deal with. I've found that if you drill as near center as possible and steadily increase the bit one size at a time, you can keep going until you can use the same size tap and remove what material remains. Use TapMagic, Cutting Oil, or lube oil, I've found that regular engine oil works pretty good too.
3. If you know you are going to, or have a fear of "what if I break this off" try to make it easier on yourself. Lets say you're working on an exhaust manifold Cat 3300 series engines for example....take a cut off wheel, or burr grinder and pretty much take the nuts off if you fear breaking off the studs flush with the side of the head. What this lets you do is have something to grab onto with a stud remover, pliers, or you can cut the stud down long enough to weld fresh nuts onto whats left of the stud. Welding removal nuts to the studs will usually creat enough heat to help the studs out a little better.
4. Same thing with bolts....you tried an air gun...nothing, you tried a breaker bar....nothing. Heat the head up with the torch and still nothing? Cut the head off and try to save some something to grab onto. Usually the threads are corroded. PB blast and really any other oil lube travels towards heat. If you heat the stud or nut up, let it cool for a bit, then soak it with lube. THe lube will work its way into the threads slowly.
5. When worse comes to worse, and it pisses me off when I see this but it works. You're out of Helicoils or would take too long to get.....Say you drill out a 3/8" bolt and it takes the threads out too. Don't sweat it too much. If you've got metric Taps you can try to tap it out to 10mm, or the next Std. size up.
1. If the bolt is big enough and not blind holes. Drill a decent size hole through the center of it. This acts as a relief for the melted bolt to run out of. Now remember, yes its a torch, but be very surgical and delicate with it. You can actually melt away at the bolt til you start seeing threads appear of whatever it is you are working on.
2. Blind holes are a little trickier to deal with. I've found that if you drill as near center as possible and steadily increase the bit one size at a time, you can keep going until you can use the same size tap and remove what material remains. Use TapMagic, Cutting Oil, or lube oil, I've found that regular engine oil works pretty good too.
3. If you know you are going to, or have a fear of "what if I break this off" try to make it easier on yourself. Lets say you're working on an exhaust manifold Cat 3300 series engines for example....take a cut off wheel, or burr grinder and pretty much take the nuts off if you fear breaking off the studs flush with the side of the head. What this lets you do is have something to grab onto with a stud remover, pliers, or you can cut the stud down long enough to weld fresh nuts onto whats left of the stud. Welding removal nuts to the studs will usually creat enough heat to help the studs out a little better.
4. Same thing with bolts....you tried an air gun...nothing, you tried a breaker bar....nothing. Heat the head up with the torch and still nothing? Cut the head off and try to save some something to grab onto. Usually the threads are corroded. PB blast and really any other oil lube travels towards heat. If you heat the stud or nut up, let it cool for a bit, then soak it with lube. THe lube will work its way into the threads slowly.
5. When worse comes to worse, and it pisses me off when I see this but it works. You're out of Helicoils or would take too long to get.....Say you drill out a 3/8" bolt and it takes the threads out too. Don't sweat it too much. If you've got metric Taps you can try to tap it out to 10mm, or the next Std. size up.
RayF
Senior Member
A while back I was called out bush to an Industrial hay press. It had an 18 inch hydraulic cylinder and from memory it had about 10 or 12 X 1.1/4 UNC bolts hoding it on. My job was to drill them out bigger to take bigger bolts as the inch and a quarter were breaking. It all went well until they tell me I'm about done except for the broken one in the press itself. News to me! Then they tell me we got you one of those cobalt drills so I can drill out the broked ezi out
So I had a look and here is this bolt broken off half way down the hole and the broken ezi out and as well the bolt has sheared at a 45 deg angle. I ended up getting in there with a carbide burr and getting a flat off to one side of the ezi out. I then drilled through with a 1/4 drill bit. I went through a box full of the farmers gas cutting tips and picked the best. Got everyone around with fire hoses and buckets and melted it out.As others have said it came out easy and left the threads perfect. Not that it mattered. It had to be drilled out anyway.
So I had a look and here is this bolt broken off half way down the hole and the broken ezi out and as well the bolt has sheared at a 45 deg angle. I ended up getting in there with a carbide burr and getting a flat off to one side of the ezi out. I then drilled through with a 1/4 drill bit. I went through a box full of the farmers gas cutting tips and picked the best. Got everyone around with fire hoses and buckets and melted it out.As others have said it came out easy and left the threads perfect. Not that it mattered. It had to be drilled out anyway.