Beaver 53 makes a good point on the grounding close to the work. The other consideration is the farther you ground from the weld area the more possible bearings that can have current pass through them. It is not unusual to have bearings fail on heavy equipment from maintenance welding that is grounded poorly. They get small areas around the contact between the race and bearing where the arc tracks across them.

1950 Chevrolet 3/4-Ton 3600
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