Gunner wrote:

Which welder? And the teeth should be against the backstops, not the
spine

It's the little Dayton one, model 4TJ96. The manual disagrees with your
method, it says "Firmly seat back of blade against back alignment surface
of welder jaw and clamp blade tight with the jaw clamping handle."

To answer Harold's question, maybe a slitting saw would work OK. The
jaws only open about .030"-.035" or so, and the reference surface is at
the back of what amounts to a slot. I'll think about that some more.

Grant