These caster wheels have blue non-marking injection molded thermoplastic rubber tires that are mechanically bonded to a polyolefin ( industrial plastic ) center.  Tire is made of copolymer rubber with excellent elastic properties.   What makes this elastomer special is its ability to bounce. Resilience in a wheel material is a necessary feature in order to protect the cargo being moved. The tire on this wheel is a resilient synthetic elastic rubber. It provides the performance of a cushion ride without the expense associated with a tire made using natural rubber.

They are popular on equipment in Pharmaceutical Laboratories, Hospitals, Food Service and other Institutional applications. These caster wheels provide a softer ride than polyurethane and yet withstand exposure to many chemicals and solvents. They can be used in industrial applications which do not involve shock, overloading, abuse, obstructions, poor floors or storage (standing) loads.

Soft rubber provides more desirable operating characteristics than any other wheel material. These blue soft rubber wheels are non-marking, quiet, absorb shock (prolonging equipment life and protecting cargo), can roll over small objects, protects costly floor surfaces, and minimizes vibration. 

Load capacity ratings do not take into account the effort required to manually move a load (drawbar pull measured in pounds). If cargo is to be moved manually on these blue soft rubber caster wheels, reduce capacity ratings by 50% and select the largest practical wheel diameter.  These caster wheels should not be left standing under load for extended periods as the tires may take a permanent “set” or develop flat spots. They can be used on almost any dry factory floor. The bonding agent which holds the rubber tire to its polyolefin center can be affected by exposure to some chemicals, impact, overloading, and the buildup of heat.