Thread: HELP!!!! stripped bolt head!!

Originally Posted by BradC

...my neighbour has an EDM...

Tell us more.

Originally Posted by AK83

Worked absolutely perfectly...

Hmmm...something else I can buy myself for the stocking. Can never have enough options when removing stuffed bolts.

Originally Posted by BradC

EDM is Electric Discharge Machining. Otherwise known as a Spark Eroder. In this context it's a spark head mounted to a single axis motorised quill. You line the electrode up over the centre of the thing (bolt, snapped drill bit, broken EZ out) and flood it with distilled water. The electrode is lowered until the Sparks start and then it slowly bores the centre out of the target with rapid and continuous little blasts of plasma. Due to the nature of the operation and the dielectric flood it doesn't heat the target and makes a neat and tidy hole.

In in the context of thread removal it generally allows stripping the guts out of the fastener without damaging the surrounding threads, and the remainder can be peeled out with a dental pick.

Thanks BradC,

My bad. I should have said I know what EDM is. I bought a book years ago on how to make an EDM using shaped carbon rods, as opposed to the wire type. Work could only be done in the horizontal, and any part with a stuck bolt would likely have to be removed from the main body of the machine. Got 95% of the components but began having 2nd thoughts with regards to building it due to the high voltages produced.

I was more curious that your neighbour has one - made me wonder if the technology has moved on and it has become an expensive handy man tool, which I'd love to have