The most popular polyurethane wheels are those with 3/8” thick tread. Four distinct compounds and hardnesses provide plenty of choices and potentially great solutions to many plant challenges. The classic Duralast® is a proven overall performer, and comes standard with three different bearing types, plain bore, and diameters up to 20”.A large number of these are available for quick delivery from stock. In addition to Duralast®, Hamilton offers tread compounds that enhance ergonomics (SP), added capacity (D70), and continuous duty applications (TR).