We want to spot weld SS 202 rods for wire mesh.Rod dia size is 4 and 5 mm.We would like to know the weld parameter settings like weld time, current, force etc.for perfect welding without getting any blackening spots. Finishing is a very important aspect.

I know these guys do a lit of welding with wire mesh:

www.bwire.com

as an individual, I have worked with them in the past and they do some neat things with fabrication.  May want to shoot them an e mail for your welding wire mesh needs.