Removing Sheared Bolt

[naurts]

... doing trailer maintenance and managed to shear off one of the bolts securing a roller post ... It's snapped off flush so I cannot get a grip on the remainder of the bolt ...


Your thoughts on removing the bit that's left, still securing the roller post ? Any particular brands of bolt extractors you would recommend ?


Naurts

[robothefisho]

A drill or an oxy.

[peterbo3]

Do not waste money on extractor kits. Punch, then small drill bit for pilot hole, then large drill bit. Do it slowly with cutting fluid or kero using the largest power drill that will fit (assuming the boat is still on the trailer).

[Gon Fishun]

Thin disc on an angle grinder.

[marto78]

I had about 6 or 7 that broke off on my trailer a few months ago and I went and bought a 10mm cobalt drill bit from Bunnings and drilled them all out with the battery drill. Doesn't take long at all with one of these bits.

[odieman150]

Always used ezyouts but like the cobalt drill bit idea

[Noelm]

forget the ezyouts, when you break one, you're in a whole new world of pain.

[Fed]

10 times easier to drop the boat on the grass.

Portagas & Penetrene are your friends.

I'm never going to break another bolt but if I did I'd cut a slot across the bolt with a hacksaw & use an impact driver even if it meant cutting into the nut or bracket a little. All depends on what you've got to deal with.

[Spin]

This is another way you can try
Sit a flat washer over the top of the bolt weld the inside of the washer to the top of the bolt
and then weld a nut to the washer
and while it is still very hot you should be able to use a spanner to remove it
the welding heats everything up as well so be fast

[shaungonemad]

I had this problem not so long ago and I just used a center punch and started with a small drill and worked my way up it was done in no time.

[STUIE63]

Just make sure your drill hole is on centre

[tunaticer]

Best way to remove the bolt without damaging threads or mounts is to drill a 5mm hole in the middle of the bolt, then weld a nut onto the top of the bolt and let it cool. Shrinkage of the bolt because fo the centre hole will release it nicely from the mount.
For a 12mm bolt I would plug weld a 10mm nut to it.
I am yet to have one that does not remove the bolt with this method.

[naurts]

Thank you for all of your replies ... as always, a wealth of info out there from your collective experience ...

The job is now done and offending bolt has been removed successfully ... and sharing my experience:

1. I didn't do any welding (don't have one)
2. Decided not to use an extractor bit (based on advice from this Forum and being nervous about tool snapping off in the hole)
3. Centre punched the sheared bolt and used a number of cobalt bits to drill holes increasing in size to 12mm
4. As advised, it was important to get the hole as centred as possible
5. Lubricated the bits with WD40 while drilling to minimize heat

Once again thanks for all the replies ...

Regards ... Naurts

[BigE]

file the broken bolt flat - centre punch the bolt shaft - drill a pilot hole - redrill with the bigest drill you can while leaving some meat for an ezy out to bite into - go to a tool shop ( no not bunning or masters i said a tool shop) buy a good quaility ezy out ( it will be expenisve twice the price of a good drill bit) buy a can of "bolt Off" (white and blue aerosol can) - install the ezyout until it gets a good grip - spray with bolt off (do not breath in bolt off it is really really bad for you) wait 5 mins spray again use plenty dont be shy - now puy slow even pressure on the ezy out ( use a tap n dye handle not a spanner or heaven forbid a shifter to turnthe ezy out bit)

BigE (experienced bolt snapper)