Capacity up to 250 pounds per caster. These institutional stem casters are ideal for most types of institutional equipment, and are offered with a wide selection of wheels. Use the Polyolefin ( Industrial Plastic ) wheel for “Standing Loads”. Polyolefin wheels eliminate the possiblilty of a flat spot developing if the castered equipment is left parked for a prolong period. Threaded Stem Casters should NOT be used as a “Leveling Device”! Capacity ratings are based on the weight being directly on the top of the swivel bearing, not somewhere above it on the threaded stem.