The locking spring should give initial pressure at near zero grip without material in the clamp. The spring should not be bent or distorted. The lock assembly should rotate freely without binding and must rest fully on the stop pin. Cams and pads are vital parts of a clamp and are exposed to wear. Use on one size plate thickness will cause wear only in one area of the cam working surface.
Replacement is required sooner than when a cam is used to handle different plate thicknesses.
Examine the cam surface. Teeth must be sharp and free of foreign material. Refer to the manufacturers' operating instructions. Inspect clamps visually before each lift. Use the correct clamp for a job.