Swivel caster with PP hub and PUR tread, 70 kg

Swivel caster in PUR with polypropylene hub and bolt hole

This is a swiveling caster with a tread in cast polyurethane and a hub in polypropylene, built for equipment and lighter carts that have to be maneuvered in tight spaces. The bracket rotates 360 degrees around the bolt hole, so the wheel follows the turn and makes the cart easy to aim even in narrow aisles. The tread has a hardness of 98 degrees Shore A, a fairly hard polyurethane that holds its shape under load and starts rolling without unnecessary force.

The hardness is what governs how the wheel behaves in operation. A hard PUR has low rolling resistance and gets going easily, which shows over a working day with many starts and stops. At the same time the polyurethane is far gentler on the floor than a plain plastic wheel; the tread stands up to wear and resists most oils, greases and mild chemicals in a workshop environment. A softer wheel, say a rubber around 70 Shore A, would have absorbed impacts better and run more quietly on uneven ground, but would also have given higher rolling resistance and carried less load. This wheel sits toward the hard end and therefore suits places where it rolls a lot on even floors.

The polypropylene hub is light and corrosion free, which keeps the weight of the whole caster down and takes moisture and cleaning without rusting. Inside the hub sits a plain bearing. It is a simple, maintenance free solution that handles dust and wet, and since it has no moving balls it copes with dirty environments without trouble. The plain bearing gives slightly higher rolling resistance than a ball bearing, but for the loads this wheel is built for it is a tough and reliable design.

The wheels come in diameters from 50 to 100 mm and carry up to 55 kg per wheel. A larger diameter rolls more easily over joints, thresholds and cable ducts and lowers the rolling resistance, while a smaller one keeps the overall height down where space is limited. Mounting is by bolt hole, a single bolt hole through the bracket, which works well on fork or tube constructions where a top plate does not fit.

The caster is available with both a wheel brake and a total lock brake. A wheel brake locks the wheel itself so the cart does not roll away, while the total lock brake locks both the wheel and the swivel and thereby parks the cart completely still. That is practical at stations where the equipment has to stay put during work, or on sloping floors where an unlocked cart can otherwise start to move. You choose brakes per caster as needed; fitting two of four casters with a brake is often enough for the whole cart to stand safely.

One thing worth thinking about is the relationship between diameter and swivel action. On the smaller diameters in the range the caster swivels easily even when the cart is standing still, while the larger ones roll better over unevenness but take a little more effort to turn on the spot.

Where does it fit? Swivel casters in PUR with a polypropylene hub often sit under instrument carts, serving carts, lighter material carts, cleaning carts and mobile racks in industry, warehousing, workshops and public environments. The hard tread makes it a good choice on painted or ground concrete, tile and vinyl flooring where you want low rolling effort and consideration for the floor at the same time.

Think about the operating environment. Polyurethane is happy at normal indoor temperature and in dry to slightly damp environments. If the caster stands still for a long time under full load, the tread can take a temporary flat spot that rolls out after a while; that is normal for polyurethane. For really heavy loads or uneven outdoor surfaces you should choose a wheel with a larger diameter and a heavier hub.

Are you unsure which diameter and load capacity suit your cart? Get in touch and we will go through the load and the surface together.