Green Polyurethane Tread on Cast Iron Keyed Drive Wheel Polyurethane on cast iron is the most versatile and cost-effective industrial wheel on the market. Green Polyurethane Tread Wheels Keyed drive wheels come in 4”, 5", 6”, 8” & 10" diameters. The polyurethane tread is liquid cast and chemically bonded to a Class 30 solid web cast iron center. The non-marking and non-sparking tread protects floors, rolls quiet and is resistant to most chemicals, while the high capacity load bearing wears like iron. Bore & Keyway Dimensions Keyed drive wheels come in a wide range of standard and metric bore sizes- see chart above. Set screws are also included- one on the keyway and one 90 degrees from it. Finally, a 90-95 Shore (A) durometer is also included, making this keyed drive wheel a great solution as a new or replacement part. Wheel Width Keyed drive wheels come in 1.5", 2" & 3" widths. Product listings are based on these attributes so when conducting your search be sure to specify one of these three widths to view all available wheels in that category. Service Caster is one of the largest caster and wheel companies in North America. For more than 25 years, we have designed, manufactured, assembled, and distributed casters worldwide from our location in West Reading, Pennsylvania. The Service Caster brand encompasses a broad range of casters and wheels designed for light to extra heavy duty applications and everything in between. Finely crafted from the highest quality materials, our casters will keep your projects rolling for years to come. Quality. Reliability. Excellence. Count on us to move you forward.