Choosing a Tread Material
Wheel tread material (or compound) can be a large and rather complex issue. Multiple options are available. First you must determine your load capacity, then the type of floor you will be rolling on. The environment you are working in can have an affect on your choice as well. If there is high heat, greasy floors, caustic materials, etc., there are special compounds for many special applications.
First, a quick note on hub material:
Hub Material – The hub on a caster wheel is much like the wheel on your vehicle, where as the tread is like the tire. Caster wheel hubs are made from many different materials. The 3 most common are Steel, aluminum, and poly. Steel will normally always give you the highest capacity, but hub material is normally more of a preference than anything.
The following compounds are listed generally from softest to hardest.
Dyna-Tred TPR – Thermoplastic rubber resists chemicals, caustics, oils, acids, and wear. Rugged polypropylene hub won’t dent, mar, fade or stain. Tread and hub are double bonded and mechanically interlocked to eliminate tread separation. Gives dollies, carts and trucks a soft and cushioned non-marking ride. Temperature operating range is -40 degrees F to +180 degrees F. Durometer is 70A.
Soft Rubber – This composition rubber wheel combines a soft rubber tread with a hard rubber core for quiet movement, a cushioned ride, and maximum floor protection. Temperature operating range is -40 degrees F to +158 degrees F. Durometer is 75A.
Mold-on Rubber – Cushioned rubber tread permanently vulcanized to a semi-steel core is recommended for quiet movement with heavy loads. Molded core provides added strength with a reinforced, double-thick hub. Vulcanized rubber-tread wheels are standard with roller bearings. Temperature operating range is -40 degrees F to +159 degrees F. Durometer rating is 75A.
Polypropylene – This polypropylene wheel has a light weight, low cost, high impact strength. It resists water and chemical absorption, even stands up to repeated steam cleaning. Non-marking tread provides excellent floor protection. Polypropylene makes the strongest, longest lasting, and most economical wheel in many caster applications. It’s available with plain or roller bearings. Temperature operating range is -20 degrees F to +180 degrees F. Durometer is 60D.
Dyna-Tred PU Wheels – Polyurethane tread for high load capacity and extended wear. Protects floors and resists chemicals, caustics, acids, and oils. Rugged polypropylene hub will not dent, mar, fade, or stain. Tread and hub are mechanically interlocked to eliminate tread separations. Temperature operating range is -40 degrees F to +180 degrees F. Durometer is 90A.
Mold-on Polyurethane – Polyurethane tread permanently attached to a metal core delivers a cushioned ride, excellent mobility, and extended life under extremely heavy loads. Duro-Tred wheels protect floors and loads better and will wear four to ten times longer than other wheel materials. Standard with roller bearings. Temperature operating range is -40 degrees F to +180 degrees F. Durometer rating is 95A in standard.
Thermoplastic – Reinforced Thermoplastic material and specific processing create this high performance, durable, and cost effective wheel. The RT series of wheels, designed for use in the Faultless brand 1400 and 400 Series Casters, are ideally suited for food processing, tool storage, sanitary maintenance, and applications requiring easy mobility under heavy loads. They are extremely resistant to water, chemical absorption, and steam cleaning. Standard wheel operating temperature range is -20 degrees F to +250 degrees F and the High Temperature version range is -20 degrees F to +480 degrees F. Durometer is 65D.
Hard Rubber – Hard-rubber molded composition all through, this wheel is impervious to oils, greases, and gasoline. It combines many desirable characteristics: high-loading rating, good mobility, high-impact resistance, and good floor protection. Temperature operating range is -40 degrees F to +158 degrees F. Durometer is 75D.
Phenolic – Phenolic compound reinforced with macerated fabric makes a high-strength, high-impact wheel resistant to oil, gasoline, even dilute acids. Compression-molded under extreme pressure, these wheels gain a dense uniform consistency. Phenolic wheels are non-marking, non-conductive, and spark-proof. They are available with plain or roller bearings. Will not warp or swell in a temperature operating range of -40 degrees F to +300 degrees F. durometer is 75D.
Sintered Iron – Powdered iron, compacted and sintered to cast-iron strength, makes a concentric and smooth tread that runs quietly and protects floors. Standard with plain bearings. Temperature operating range is -40 degrees F to +500 degrees F.
Semi-Steel – Cast iron toughened with steel, this wheel has extremely high load ratings and exceptionally long wear life. It’s recommended for rough wood and concrete floors – a good choice for moving heavy loads in manufacturing and warehousing. Long-life features include a heavy tread and plain or roller bearings. Ideal in extreme operating temperature ranges of -40 degrees F to +800 degrees F with optional high temperature grease.