Defender D4 Series Colson Casters

Standard zinc-plated casters protect only the surface layer. Once the zinc wears through at contact points, stress areas, or scratches, the underlying steel corrodes rapidly. The D4 Series in stainless steel uses corrosion-resistant material throughout the entire component, not just as a surface treatment. Even the zinc-plated D4 models use upgraded plating thickness and sealed bearings that far exceed standard coated casters.

For direct washdown exposure and USDA/FDA-inspected areas, stainless steel D4 models are the recommended choice. They withstand daily high-pressure washing with caustic and acidic sanitizers without degradation. Zinc-plated D4 models are suitable for adjacent dry storage areas or light-moisture zones where full stainless is not required.

Polyurethane and nylon wheels perform well in wet environments because they resist moisture absorption and maintain traction on wet floors. For cold storage below 0 degrees Fahrenheit, nylon is generally preferred over polyurethane because it retains its mechanical properties at lower temperatures.

The 304 stainless steel components resist a wide range of acids, alkalis, and solvents. For specific chemical compatibility, verify the wheel material against the chemical in question. Nylon wheels offer the broadest chemical resistance, while polyurethane handles most common industrial chemicals except concentrated solvents.

Available in stainless steel and zinc-plated configurations, the D4 Series protects against daily washdown spray, caustic cleaning agents, saltwater exposure, and high-humidity environments. Stainless steel models use 304-grade stainless in the yoke, top plate, axle, and fasteners, eliminating every corrosion point that causes conventional casters to fail. Sealed precision bearings in both the swivel raceway and wheel hub keep contaminants out and lubrication in. Wheel options include polyurethane, stainless steel, nylon, and thermoplastic rubber, each selected for chemical compatibility and washdown durability.

Load capacities in the D4 Series range from approximately 200 lbs to 1,200 lbs per caster, covering the vast majority of carts, racks, shelving, and mobile processing equipment found in regulated food-grade and pharmaceutical environments. If your facility is subject to USDA, FDA, or HACCP inspection standards, the Defender D4 Series helps you maintain compliance at the caster level.