This is a nice, clean, vintage heavy duty 1.5" capacity single C-Clamp, marked "233".   As you can see in the pictures the clamps are in good shape, no rust or pitting, very clean, not bent up. This clamp has an 3.5" long frame and the thickness at the clamp pad is .40" diameter, and the threaded screw is 1/4" diameter. It was very well made, and still is in great shape!