Jonathan Webb
Member
- Messages
- 413
- Location
- West Sussex, England
I've got two amusing m8 sheared bolts in a heat exchanger (pic shows the first broken one. Elbow is now off). I'm going to try and weld nuts on today with my buzzbox arc welder, but don't feel hopeful as access isn't great and I'm not exactly great at welding.
If I have to resort to drilling them out, it makes sense to me to use a left hand drill bit as I understand that sometimes this can unscrew the bolt and if not, you have to extract the thread remains anyway.
My main question is how close to the bolt size do you go -7mm, 7.5mm, less?
Also, where can I buy a reasonable to decent single drill bit? Most of the Dormer suppliers do packs of 10 for this size. I'm open to any make that is adequate. Thanks.
FWIW, I've heated them to just glowing twice, I haven't got a proper impact driver, but gave them what for with a chisel in my SDS drill on hammer only. They've spent the night annointed with plusgas.
If I have to resort to drilling them out, it makes sense to me to use a left hand drill bit as I understand that sometimes this can unscrew the bolt and if not, you have to extract the thread remains anyway.
My main question is how close to the bolt size do you go -7mm, 7.5mm, less?
Also, where can I buy a reasonable to decent single drill bit? Most of the Dormer suppliers do packs of 10 for this size. I'm open to any make that is adequate. Thanks.
FWIW, I've heated them to just glowing twice, I haven't got a proper impact driver, but gave them what for with a chisel in my SDS drill on hammer only. They've spent the night annointed with plusgas.