The replaceable ball swivels to allow for better self-alignment on uneven surfaces. A Viton O-ring holds the ball in place while keeping contaminants out and providing smooth ball movement. The housing is made from alloy steel, heat treated to Rc 43/46 with black oxide finish. The urethane surface is permanently bonded to a 300 series stainless steel ball. The non-marking, non-staining urethane provides excellent protection against damage on delicate work surfaces. The “bubbled” texture of the urethane top offers firm holding and allows air to escape so no suction is created between the contact surface and the top of the rest pad as it is compressed. Because the top is made of urethane they offer superior abrasion and wear resistance. They are available in three durometers to meet a wide variety of application needs. Replacement balls and O-rings can be ordered separately. Load compression is based on the weight to compress the urethane surface .032". These ratings can vary greatly depending on temperature and other factors that normally affect the performance of urethane.

SELECTING A DUROMETER
The 35 Durometer should be used for very light duty applications only. The hardness is equivalent to a soft pencil eraser and can tear easily. The 60 Durometer should be used for medium duty applications. The hardness is equivalent to an automobile car tire and does not tear easily. The 80 Durometer should be used for heavy duty applications. The hardness is equivalent to heel of a dress shoe and is almost impossible to tear.