Schaefer's Blocks rely on a variety of sheaves designs and scorings. Schaefer sheaves are design to be compatible with Schaefer products. There is a risk of incompatibility or failure when using Schaefer sheaves in blocks manufactued by anyone other than Schaefer Marine.
Delrin Sheave with Delrin™ Ball Bearings are used in line applications to reduce friction. To provide the maximum load bearing capability, Schaefer's designed their Delrin™ ball bearing sheaves and inner races with curved surfaces to match the ball races. The resulting sheaves has much higher Safe Working Load than others manufacturers.
Part Number: 62-153-02A