The housing and integrated screw-on plates of the heavy-duty minis are made of galvanised industrial steel, while the hub is made of solid cast iron. The running surface of the wheels is coated with abrasion-resistant and highly temperature-resistant polyurethane (PUR). High-quality materials and workmanship as well as sophisticated technical details allow the extremely hard-wearing castors to transport heavy loads easily, to be used continuously in the workshop or to move heavy pieces of furniture easily and gently on the floor. A total locking device fixes furniture and equipment securely in the desired position. Particularly high quality: The wheel axles of the heavy-duty minis are not conventionally riveted, but bolted; this allows the bolted connection to be retightened quickly. A ball and cage assembly in the screw-on plate and double ball bearings ensure the best manoeuvrability, low-noise movement and optimum running. Fastening is quick and easy: simply screw on and roll off.