Posted by chriscase on Wednesday, October 18, 2006 at 3:59PM :
In Reply to: Fishplating frames... posted by Jonas on Wednesday, October 18, 2006 at 3:43PM :
Any hole or weld will cause a 'stress riser' where the frame will flex in one place, and work harden/fatigue there. My FFPW has cracked flanges, just in front of the cross member at the front of the rear leaf springs. The truck had an extensive dock bumper welded to frame, bed, etc, that made the rear section rigid, so all the flex happened at the one point.
The no "weld or drill" signs are usually on heat treated frames. I've always assumed heat-treatable steel is more prone to work hardening than mild steel.
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