There are a number or different types of clamps. One type is simply a friction clamp that uses a set screw to keep the clamp from sliding. Another type uses spiral pins driven between the clamp and the casing to supply the holding force. Other have dogs (or teeth) on the inside that actually bite into the casing. Any clamp that might scar the surface of the casing could be considered unusable where corrosion problem exist. One of the littleemphasized benefits of centralizers is that they reduce pipe sticking caused by pressure differentials. The force holding casing against a permeable section in the hole is proportional to the pressure differential across the pipe and to the area of the pipe in contact with the wellbore isolated from the hydrostatic pressure by thickened mud cake.
design with case hardened inserts embedded in collar ID to provide maximum holding resistance.
Mego afek FASGRIP™ Stop Collars with dogs size: 16 Specifications: