Simply tighten the topmost knurled nut to compress the rubber for a snug fit.
5 Inch Blue Polyurethane Swivel 1 Inch Expanding Stem Caster Brake, 2PK Service Caster is unsurpassed in quality, reliability, and excellent customer service. Listing is for a set of four (4) Service Caster Series #20 1" expanding stem swivel casters, two (2) with top locking brakes, with 3-1/2" diameter by 1-1/4" wide blue polyurethane wheels capable of supporting a total weight of 1,000 lbs. Finely crafted with a bright zinc plated finish and heat-treated ball bearing raceway, this versatile caster is ideal for work tables, shop projects, or any equipment with round or square tube legs. The Series #20 features an innovative expanding stem that can easily adapt to the inside diameter of the opening, allowing for a secure fit in round or square tubes.