PU vs rubber vs nylon caster wheels.
Three tread materials cover most of the caster world. Each is the right answer somewhere and an expensive mistake somewhere else — this comparison names both places.
Polyurethane: the indoor default — high load, floor protection, quiet, cut-resistant; fails on heat and on rough ground shock. Rubber: the shock absorber — rough floors, grip, institutional quiet; fails under sustained heavy load and around sharp swarf. Nylon: the capacity bargain — highest load per dollar on dry hard floors; fails on noise, floor marking and shock. Choose by floor and failure mode, not by habit.
| Property | Polyurethane (PU) | Rubber (elastic / TPR) | Nylon |
|---|---|---|---|
| Load capacity | High | Light–moderate | Highest per size |
| Floor protection | Excellent, non-marking | Excellent, non-marking grades | Poor — hard, can mark and chip delicate floors |
| Noise | Quiet | Quietest | Loud on hard floors |
| Shock absorption | Moderate | Best | Worst — transmits impact |
| Rolling resistance | Low | Higher under load | Lowest |
| Heat | Poor — softens and degrades | Poor | Moderate |
| Wet / chemicals | Good; grade-dependent | Good; compound-dependent | Excellent chemical resistance |
| Signature failure | Flat-spotting under standing load; delamination in cheap builds | Cutting and chunking around metal swarf | Cracking under shock; skating on wet smooth floors |
Polyurethane: the default, with two warnings
PU earned the default position honestly: no other tread carries its load, protects floors and runs quietly in one package. Warning one is heat — sustained high temperature destroys it, which is why the phenolic line exists. Warning two is build quality: PU performance depends on the bond between tread and core and on the compound's hardness being what the quotation says. Both are sample-checkable, and both are in our locked specification for the PU line.
Rubber: buy it for the floor's sake and the load's sake
Rubber's gift is compliance: it absorbs the dock plate, grips the dusty floor, and runs silent in hospitals and hotels. Its limits are load and sharp environments. Around machining swarf, rubber treads cut and chunk; under sustained heavy standing loads, softer compounds take a set. Institutional TPR is the refined end of this family — see the rubber line for where each compound belongs.
Nylon: the honest bargain
Nylon (and its polypropylene cousins) carries more load per dollar than anything else here and shrugs off chemicals that attack elastomers. The price is paid in noise, floor kindness and shock: a nylon wheel on tile is loud, on a delicate floor is a liability, and under impact loads can crack where an elastomer would flex. In dry, rough-and-ready industrial duty — stillages, factory dollies on worn concrete — it remains the rational choice, and pretending otherwise would be salesmanship, not guidance.
The fourth material in the room
Phenolic belongs in this comparison only to be pointed elsewhere: it is the heat specialist, covered in the high temperature line. Cast iron itself — the tread-less option — survives where everything else melts or shreds, at maximum floor aggression. If your application points at either, the conversation has left the PU/rubber/nylon triangle, and the RFQ is the right next step.
Related guides
Specification first. Price second.
Every guide on this site ends at the same place: a locked specification and a sample that proves it.