Polyurethane is the default choice when you need load capacity close to nylon but must protect painted concrete or epoxy floors. RollMaster casts PU wheels in-house on grey iron and steel cores.
PU wheels offer low rolling resistance, good grip, quiet running and resistance to oils and many chemicals — the standard wheel for AGV/AMR platforms and indoor material handling.
Process Overview
Polyurethane caster wheels combine a hard core (grey iron, steel or aluminium) with a cast or injected PU tread. The core carries the load; the tread protects the floor, grips, and rolls with low resistance.
PU tread hardness (Shore A), the bond between tread and core, and the compound recipe determine load capacity, noise and flat-spot resistance — which is why PU quality varies more between suppliers than any other wheel material.
Material Grades & Properties
Polyurethane (PU) Grades We Machine
| Grade | Standard | Characteristics |
|---|---|---|
| Shore A 92-95 | cast / injected | default heavy duty tread |
| Non-marking compounds | grey / red | for protected floors |
| AGV-grade PU | batch-documented | stable rolling resistance |
Key Properties of Machined Polyurethane (PU)
- ✓High load capacity with floor protection
- ✓Low rolling resistance, quiet running
- ✓Resists oils and many chemicals
- ✓Typical range -20 °C to +80 °C
Typical tolerances:Batch hardness and adhesion checks
Applications for Polyurethane (PU) Parts
- AGV/AMR
- trolleys on painted floors
- heavy duty carts
- cleanrooms
Engineering Notes for Polyurethane (PU)
Cast PU on grey iron or steel core; injected PU for volume sizes.
Finishes for Polyurethane (PU) Parts
- Zinc-plated bracket
- Stainless bracket
Specifications
- Shore hardness 92A–95A standard, other compounds on request
- Injected and cast PU production lines in-house
- Non-marking grey and red compounds available
- Temperature range typically -20 °C to +80 °C
Finishes
Zinc-plated or stainless brackets
| Bracket finish | What it does | Specify it when |
|---|---|---|
| Zinc plating (blue/white) | Baseline corrosion protection | Standard dry indoor use |
| Chrome plating | Hard, decorative, easy to clean | Visible / cleanroom-adjacent equipment |
| Powder coating | Custom color, good corrosion resistance | Brand colors, outdoor-adjacent use |
| Stainless steel 304 | No plating to fail | Washdown, food, medical |
| Stainless steel 316 | Resists chlorides | Salt, brine, marine air, harsh cleaning chemicals |
Testing
PU-to-core adhesion and hardness checked per batch
| Selection factor | Rule of thumb | Effect on performance |
|---|---|---|
| Load sizing | Total load ÷ 3 (not ÷ 4) | On uneven floors only three wheels carry the cart |
| Wheel diameter | Bigger rolls easier | Larger wheels cut push force and bridge gaps |
| Tread hardness | Softer = quieter, harder = easier rolling | Pick the softest tread that carries the load |
| Bearing choice | Precision ball for manual pushing, roller for heavy loads | Bearings dominate rolling resistance at high load |
| Swivel vs rigid | 2 swivel + 2 rigid is the standard cart setup | All-swivel carts wander; all-rigid carts cannot steer |
| Floor condition | Rough floors need bigger wheels and softer treads | Small hard wheels on bad floors destroy both |
Related products
Capability commitments on this page are owner-confirmed (2026-09-29).