The C Washer is an open-sided washer that slides around the clamping stud from the side — you don’t need to remove the nut or disassemble anything to place or remove it. This speeds up fixture setup and adjustment, especially on multi-clamp configurations where you’re repositioning frequently.

The open slot is sized to clear the stud shank while keeping enough bearing area to distribute clamping force effectively. It sits between the nut and the clamp surface, doing the same job as a full washer but with faster placement.