8" x 2-1/2" Phenolic Swivel Caster Heavy Duty Industrial Grade - 1800 lbs. Cap.8" x 2 1 2" Industrial Grade Phenolic Wheel Swivel Caster The Phenolic wheel is made of phenolic resin and macerated canvas, which provides smooth rolling and resistance to extreme temperature shifts. Phenolic wheels are resistant to oils, greases, and some liquids, but they should not be used on rough surfaces or wet environments. Tread: Phenolic Resin With Macerated Canvas Core: Phenolic Resin With Macerated Canvas Bearing: Roller Bearing Rig: Zinc