These stamped steel ground clamps are standard from the factory on many welders. They work pretty well, but performance degrades in time. I could buy a nice brass ground clamp, but would rather just improve the contact and current path on this clamp.
I decided to fit some aluminum bar stock inside one half of the stamped steel spring clamp. My bar stock is 1/8 inch x 3/4 inch. The space inside the stamped steel clamp handle is about 9/16 inch. I used a hacksaw to trim off the excess.