4C55SD

These 4C Sheaves use an SD QD bushing, are fully compatible with other suppliers, and are designed for safe operation according to ARPM Specification. That distinguishes this sheave from the rest is that it is manufactured at the factory using a high quality cast iron, is polished, finished, and filled with phosphates. Having the high quality cast iron type we use gives a greater tensile strength and is more resistant to corrosion than the types that are most widely used. While the polished and then coated phosphate finish gives a resilience to corrosion to the sheave.