Hmmm . . If it's the steel in the header that's giving you a problem, try
drilling away from the weld area . . if this drills okay, you may have a
"tempered" situation caused by fast-cooling of the weld area. You can solve
that by annealing the affected area: heating to red hot and cooling slowly.
If it's the weld bead itself that's giving you grief, you may just have a
weld of an extra tough and hard-to-machine metal. About the best you can do
is grind thru the bead with a high speed die grinder and then finish with
the drill. Use a slow-speed drill press if possible. Good luck.
Tony
> I'm hoping one of you mechanical-types can help me out. I recently had a
> steel exhaust manifold flange welded, and now I'm trying to redrill the
> hole for the stud. I can't find any drill bits that will cut through the
> welded steel. I've tried regular high speed drill bits, titanium-coated,
> cobalt, and most of them won't even touch it. Yes, I'm using cutting oil.
> I've managed to get about 1/8" through, but the more I try, the less
effect
> I seem to have. Any ideas?
>
> Calvin Krug
> trying to rebuild my MGB
>
>
>
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