Patent ID: 8350179

Claim:
A method of preparing a resistance spot welding electrode for imparting a visible image on a weldment, the electrode having a generally round cylindrical body with a cylinder axis and a workpiece-contacting surface at one end of the body, the method comprising: shaping the electrode to create a generally flat or convex-shaped workpiece-contacting surface on the electrode; interposing a mask between the workpiece-contacting surface of the electrode and an abrasive medium to restrict access of the abrasive medium to the workpiece-contacting surface, the mask having at least one opening enabling access of the abrasive medium to the workpiece-contacting surface; and using the abrasive medium to selectively shape portions of the workpiece-contacting surface of the electrode with image-forming features other than for creating features of circular symmetry centered about the weld face of the electrode body, the image forming features comprising protrusions and/or intrusions extending, respectively, above or below adjacent regions of the workpiece contacting surface such that the workpiece-contacting surface imposes a visible reverse image in a weldment formed on a metal workpiece.