Calvin
I would agree with the other poster about starting with a pilot hole, perhaps
about 1/8". If that doesn't work, tungsten carbide drills are available but
very expensive. You could also try annealing the weld area. Heat to cherry red
with a oxy acetylene torch then slowly withdraw the torch and let air cool.
Obviously some risk of warpage here.
Good luck.
-------------------------------------
Date: Fri, 2 Jul 1999 17:51:57 -0600
From: Calvin Krug <ckrug@laf.cioe.com>
Subject: drilling exhaust manifold
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
Brian Boss
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