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.
Schaefer Delrin™ Sheaves are injected molded with UV inhibitors and monitored molding cycles lending to a strong, UV resistant product. These sheaves offer durable, lasting service for all line applications.
Schaefer 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.
The Schaefer Aluminum Sheave configuration accommodates both line and wire, providing a chafe-free surface for line while giving full support to wire to prevent flattening. Hardcoat Anodized 60601-T6 Aluminum offers superior strength and corrosion resistance.
The Schaefer Aluminum UC Sheave with Torlon Ball Bearings are an extremely low friction ball bearing sheaves that accommodate both line and wire. High strength self-contained Delrin™ bearing package, and Nomex™/Teflon™ self-lubricated bushing is used in all "UC" sheaves . The combined benefits of the design mean easier turning under the heaviest loads.