I'M HAVEING DIFFICULTY WELDING A NUT THAT HAS A FLAT ROUND PROJECTION. THE MATERIAL THE NUT IS WELDING TO IS HOT DIPPED GALVINIZED LOW CARBON AT .059 INCHES THICK . MY NUT PROJECTION IS .89 INCHES THICK. I'M WELDING THESE PARTS ON A 250 KVA WELDER USEING ELKONITE COATED ELECTRODES. I'M SUPPOSED TO GET THESE PARTS TO HOLD AT 3000PSI OR BETTER. DOES ANYBODY HAVE ANY RECOMMENDATIONS?

-- RONALD BYRD (RBYRD@SNDRSN.COM), October 11, 2002

Answers

I think we need more information about your process. Please fill us in on the following: 1. How many projections does the nut have? 2. What is the tip diameter of the projection, and the root diameter? If they are not round, try to estimate what diameter would have the same area. If you cycle the machine in no weld, the projection should sink in to the material about 0.18 inches (20% of the projection height) if the force is right. The impression left on the sheet metal would give a good approximation of your "tip diameter" of the projections. 3. What Force, Current and time are you using? Do these values agree with any published by the Ohio Nut and Bolt Co, or those on the CMW web site? 4. What is the failure mode, does it pull a button, or just pop loose? Please describe the test, is it pushed out from the back side, pulled from the front? Torqued?

-- David Bacon (dbacon@updatetechnology.com), November 05, 2002.