A million years ago I worked in a speed shop. One of my favorite things to work on was extracting below the surface stud breaks that customers brought in...
I didn't know at the time that it would be a rare occasion that I would need the extractor as much after I left the shop. I have an extractor that is about as old as I am...still works for the right size stud.
Over the years I have bought different extractors for different size studs...they should be labeled "Dispose before use" ! It seems it doesn't matter who the manufacturer is. I'm sure you have run into the same situation.
Smarter minds than I have solved this...
What do you use that is a recent purchase that actually works...? And no, don't tell me what you bought decades ago like I did...
Don't piss off old people. The older we get the less "Life in Prison" is a deterrent !
Let me clarify...I am looking for two sets specifically...a tapered spiral flute set and a tapered straight flute set...I really don't care what else is out there...I haven't liked the 8 or so sets I've bought over the last 10 or so years and I've already thrown them out. All the flutes get damaged (chips, rounding, don't grab) after one or two uses. The single one that I've had since 1975 is still going strong...I have even found that star bits work better than the junk that's on the store shelves...and I'm perfectly happy continuing to do so.
I've got some bonding connections that need to be cleaned on the boat and I don't want to break any before I get a good set of extractors. I have not one single clue what they are made of. I have a friend's John Deere snowblower engine that needs to be disassembled and cam replaced...he's already snapped one of the head bolts. A boat trailer that needs new axles and springs. Nothing exotic...just typical nuts and bolts...
I'm just looking for forum experience on what's been bought over the last few years that people are happy with...it's raining and I've got nothing better to do...
Don't piss off old people. The older we get the less "Life in Prison" is a deterrent !
I have some K-D brand ones and they only work well when the broken stud isn't that tight. Like Stick said they often swell the broken part making it worse. Many I've drilled out and tapped, either to the original threads or a larger size. You have to be really careful tapping to get rid of the shell of a broken bolt. It's easy to get the tap jammed and break it off in the hole and then you are really screwed (no pun intended). I've drilled to the point I can start seeing the bore threads and then took a punch and folded the thin shell of what's left of the bolt inward to collapse it. It's usually easy to get what's left out after that with needle nose pliers but that is very labor intensive way to do it, as in last resort.
One option I've looked at is drilling and tapping a smaller hole in the broken bolt but to a left handed thread and using a hard left handed thread bolt to remove the broken one if it didn't already break loose in the tapping process. Unfortunately left handed taps and bolts are pricey but they are reusable at least. Screwing a bolt into the broken off one also makes it easier to apply heat to the broken one.
There is one more extreme option which I've used where the bolt broke off close to level. You cut a short piece of steel pipe or tube and you weld down the inside to the broken bolt and use vise grips or a pipe wrench if it's a large bolt to loosen. The heat from welding it usually helps break the corrosion bond between the metals at the same time. Obviously it takes a steady hand and this is where an auto darkening visor pays for itself. Doing it without one made an already tricky job even harder.
Cherryville Chuck wrote: ↑Wed Nov 11, 2020 12:45 pmI have some K-D brand ones and they only work well when the broken stud isn't that tight. Like Stick said they often swell the broken part making it worse.
Yes...that is the problem...which is why it needs to be a good quality extractor so that it bites without excessive outward pressure. I like KD's idea to use the cutting edge relief on the flute. It allows a bit of room for the cut to go into. On real ornery bolts I've tapped after drilling so that the extractor has thread room to bite into without expanding the stuck bolt...
One option I've looked at is drilling and tapping a smaller hole in the broken bolt but to a left handed thread and using a hard left handed thread bolt to remove the broken one if it didn't already break loose in the tapping process. Unfortunately left handed taps and bolts are pricey but they are reusable at least. Screwing a bolt into the broken off one also makes it easier to apply heat to the broken one. This I've done and like it...depending on the size of the broken stud...and as you noted, makes it easy to transfer heat without torching the material around it (aluminum, paint, etc)
There is one more extreme option...No thanks on this one
I'll try the KD...they're not that pricey. I've never tried the straight flute (no taper) with matching drill bits...maybe it's time.
Don't piss off old people. The older we get the less "Life in Prison" is a deterrent !
Nick when I used the pipe and weld it to the stud method I used a stick welder and a flop down welding helmet. A wire feed and auto darken helmet would make that option much easier. i have two stick welders so I couldn't justify going out and even buying one of the 110 volt wire feeds and when I was doing lots of welding the auto darken glasses were over $400 and once again I couldn't justify that. It is pretty much guaranteed to work so you shouldn't discount it. The short piece of pipe gives good purchase for vise grips or pipe wrench and the heat will break the bond. I only used it maybe twice back when I was running heavy equipment but like I said it is a never fail method as far as I know.
The straight flutes don't grip as well but they also don't tend to swell up the broken stud as much either. I just thought of an idea. If you could ream the hole to match the taper on those they should work much better.
Cherryville Chuck wrote: ↑Wed Nov 11, 2020 7:02 pm
Nick when I used the pipe and weld it to the stud method I used a stick welder and a flop down welding helmet. A wire feed and auto darken helmet would make that option much easier. i have two stick welders so I couldn't justify going out and even buying one of the 110 volt wire feeds and when I was doing lots of welding the auto darken glasses were over $400 and once again I couldn't justify that. It is pretty much guaranteed to work so you shouldn't discount it. The short piece of pipe gives good purchase for vise grips or pipe wrench and the heat will break the bond. I only used it maybe twice back when I was running heavy equipment but like I said it is a never fail method as far as I know.
The straight flutes don't grip as well but they also don't tend to swell up the broken stud as much either. I just thought of an idea. If you could ream the hole to match the taper on those they should work much better.
Thanks for that...what I generally do is drill a hole in the center, then tap it. That makes threads on the inside for the spiral or straight tapered flute to grab. Once it sinks it's teeth into the inside threads it doesn't spread the bolt as the teeth provide relief for the flutes. Unfortunately once the flutes start to wear and chip, they don't hold as well and I'm forced to bang it in deeper...that's when it spreads the bolt apart. That's why the search for quality extractors. I'm gonna try the KD's. Watch...it'll be years before I break off another bolt...
Definitely would be nice if the drilling and tapping matched the taper...oh, well.
As for the welding...I no longer have any welding equipment...let alone the nice stuff you're talking about...
Thanks...Nick
Don't piss off old people. The older we get the less "Life in Prison" is a deterrent !
