Steel—Strong but best for dry environments since moisture will cause them to rust.

Bushing Bore—Quickly swap or service parts in tight spaces—no press-fitting or special tools required. Mount a bushing (sold separately) on your shaft and slide the pulley over it. As you tighten the included set screws, the bushing grips the shaft and draws it into the pulley, creating a final hold that is more secure than with set screws alone.