These medium-duty castors manufactured in Spain has a high-grade white nylon tread and includes a double ball bearing reinforced with hardened ball races and dust proof seals. A highly resistant pressed steel (up to 5mm thick) and has a high rust resistant double chrome coating. It is non-marking, has a high abrasion resistance with a low rolling resistance. These castors can carry high loads especially at lower speeds and are resistant to many diluted acids, alkalis, oils and greases