Dear Sr. There are many practical tests for projection welding nuts, but I would like to know a standart for test. Could be ASTM, Din, doesn`t matter. I really want to get a good weld.

-- jose a. castillo lara (jose.castillo@gm.com), September 03, 2002

Answers

General Motors has standards for this. Briefly, they want a push-out test where the part is pushed away from the surface it was welded to. They recognize that a torque test is possible, but the specs recommend a push-out test. After destruction, the "button" pulled from the sheet metal must match their spot welding test, where, for example, a 1 mm sheet requires a 4 mm "button" ripped out of it. The button size varies by sheet metal thickness. Since this spec is GM property, I am uncomfortable in going too deeply into it. I am probably over- compensating, but they are my best customer... CMW has some great info on their website, www.cmwinc.com/index.html perhaps those schedules would be of assistance.

-- David Bacon (dbacon@updatetechnology.com), October 03, 2002.