Standard polyurethane castor wheels begin to soften at around 60°C and lose most of their load capacity above 80°C. In a curing oven or autoclave environment, that's a service failure within hours — the wheel deforms, the cart drops, and you're shutting down the line to recover the load.

This guide covers the two materials designed for high-temperature castor applications: phenolic resin and hi-temp nylon.

Temperature Ratings

Material	Continuous rating	Short-cycle peak
Standard PU	60°C	80°C
High-temp PU	80°C	100°C
MC Nylon	100°C	120°C
Hi-temp nylon (PA46 / PPS)	180°C	220°C
Phenolic resin	230°C	280°C

For most oven applications in Malaysian electronics and rubber manufacturing — curing temperatures between 120°C and 230°C — phenolic is the standard answer.

Phenolic Resin Wheels

Phenolic (also called bakelite in older specifications) is a thermosetting composite: resin-impregnated fabric or paper layers, compression-moulded under heat. Once cured, it's dimensionally stable up to 230–280°C continuously.

Properties:

Very hard (similar to hardened nylon at room temperature)
Low rolling resistance when hot
Resistant to most industrial solvents and cleaning agents
Will not melt or deform — it chars rather than softening

Limitations:

Hard — will damage soft floor surfaces (polished concrete, epoxy) if used outside the oven
Brittle compared to PU — don't drop loaded carts off kerbs
Noisy on hard floors (similar to MC Nylon)
Not suitable for wet environments — phenolic absorbs moisture over time

Typical applications in Malaysia:

PCB curing ovens in electronics factories
Rubber vulcanisation carts
Powder coating line trolleys (pre-cure and post-cure zones)
Autoclave carts in aerospace and composites manufacturing

Hi-Temp Nylon (PA46, PPS, PEEK)

For applications between 150°C and 220°C where the hard surface of phenolic is undesirable, high-performance engineering polymers offer an alternative:

PA46 (Stanyl) — rated to 180°C continuous, better toughness than phenolic
PPS (Polyphenylene Sulphide) — rated to 220°C, excellent chemical resistance
PEEK — rated above 250°C, typically specified only for aerospace/pharmaceutical where cost is secondary

In practice, CastorTrade stocks hi-temp nylon (PA46 / PA66-GF) wheels rated to 180°C for the 120–180°C range, and phenolic for 180–280°C. The gap between these two materials covers the vast majority of Malaysian factory oven applications.

What About the Bracket?

The wheel material is only half the equation. A phenolic wheel on a standard zinc-plated bracket will fail above 150°C — the zinc coating oxidises and the grease in the bearing breaks down.

For high-temperature applications, specify:

Component	Standard	High-temp spec
Bracket	Zinc-plated	Electroless nickel or bare steel
Bearing	Standard grease	High-temp grease (NLGI 2, >200°C rated)
Bearing material	Standard steel	Stainless steel or ceramic
Swivel ring	Standard race	High-temp race with HT grease

CastorTrade's heat-resistant castor assemblies are pre-configured with matched brackets and bearings for the intended temperature range — no mix-and-match risk.

Specifying for Your Application

Answer these questions before ordering:

Maximum oven temperature — continuous operating temperature, not just the setpoint
Dwell time inside oven — a 10-minute cycle at 200°C stresses bearings differently from a 4-hour soak
Load per castor — heat reduces the load rating of most materials; apply a 1.5× safety factor as a minimum
Floor outside the oven — if the cart rolls on epoxy before entering, you need a material that won't damage the floor at ambient temperature
Chemical exposure — oven cleaning agents, release sprays, and flux fumes can attack some materials

Our standard stock for oven applications:

Phenolic 100mm, 125mm — rated 200 kg/wheel at 230°C
Phenolic 150mm — rated 300 kg/wheel at 230°C
Hi-temp nylon 100mm, 125mm — rated 150 kg/wheel at 180°C, better floor impact than phenolic at room temperature

Need a non-standard size or load rating? Contact us with your specification — we can source from our Taiwan and European principals within 5–10 working days.