Developed in 1986, PermAlloy® is a trademarked custom overlay process developed by and available exclusively through Marigold Works. Our PermAlloy Sheaves are manufactured from one solid steel forging with no welds in structure of sheave which make them far superior to cast or fabricated sheaves. Available in single and double groove OD size range- 8” to 153″, PermAlloy Sheaves are Rockwell C rated to 52-55 entire depth, work hardens to 60+ HRC, and proven to outlast flame hardened sheaves at least 2 to 1 and extend the life of wire rope up to 40%.