At 05:51 PM 7/2/99 -0600, you wrote:
>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,
The weld/air-cool cycle has hardened the steel. Use a MAPP or Oxy/Acetelyne
torch to heat the area you want to drill to cherry red then quench with
water. Submerge the part in a bucket if possible. This will remove the
hardening and you should be able to drill easily. Hope this helps.
Cheers,
Ross MacPherson
TC-3528 , `66 BGT, NEMGT - #11849
Surrey, BC, Canada
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