Guide to Choosing Industrial Casters by Load and Safety

Imagine a heavy workbench loaded with precision instruments toppling over due to inadequate caster capacity—the resulting damage could far exceed the value of the casters themselves. Properly calculating caster load requirements is crucial for ensuring equipment safety and reliability. This article explores industrial caster load calculation methods and provides selection recommendations to help prevent potential safety hazards and financial losses.

Castors, also known as swivel wheels or rolling mechanisms, are devices mounted beneath objects to enable mobility. Widely used in industrial, commercial, and residential settings, they support various equipment and furniture including carts, workbenches, medical devices, and office chairs. Load capacity stands as the most critical factor when selecting casters, referring to the maximum weight a single caster can safely bear under normal conditions. Appropriate load capacity selection ensures smooth operation, enhances safety, and extends caster lifespan.

The standard formula for determining individual caster load requirements is:

Single caster load = (Equipment weight + Maximum payload) / Number of casters × Safety factor

Where:

• Equipment weight: The base weight of the equipment
• Maximum payload: The heaviest anticipated load (materials or personnel)
• Number of casters: Total casters supporting the equipment
• Safety factor: Accounts for variables like uneven surfaces, shock loads, and uneven weight distribution (typically 1.25 to 2)

• Four-wheel cart: For a 50kg cart carrying 150kg with safety factor 1.5: (50 + 150) / 4 × 1.5 = 75kg per caster
• Five-wheel office chair: Supporting 120kg with safety factor 1.25: 120 / 5 × 1.25 = 30kg per caster

Selecting an appropriate safety factor significantly impacts actual load capacity and durability. Key influencing factors include:

• Surface conditions: Uneven terrain requires higher factors to accommodate shock loads
• Usage frequency: Intensive daily use warrants higher factors to reduce wear
• Load characteristics: Irregularly shaped or unstable loads demand higher factors
• Temperature extremes: Require specialized materials with adjusted safety factors
• Movement speed: Rapid motion increases impact forces

When existing casters prove insufficient, consider these enhancement approaches:

• Higher-capacity casters: Upgrade to stronger, larger models while ensuring compatibility
• Additional casters: Distribute weight across more support points (e.g., expanding from four to six casters)
• Optimized placement: Strategic positioning improves weight distribution
• Structural reinforcement: Strengthen equipment framing to properly support increased loads

Beyond load capacity, consider these factors when choosing casters:

• Material: Rubber (smooth surfaces, shock absorption), polyurethane (durability), nylon (corrosion resistance), cast iron (heavy loads)
• Size: Larger wheels reduce rolling resistance but require more space
• Type: Fixed (linear movement), swivel (360° rotation), or brake-equipped models
• Mounting: Plate-mounted, stem-mounted, or bolt-hole configurations
• Environment: Specialized options for high-temperature, corrosive, or ESD-sensitive areas

• Medical equipment: Require quiet, cleanable, maneuverable casters with medical-grade materials
• Food processing: Need corrosion-resistant, hygienic stainless steel or food-grade plastic casters
• Electronics: Demand anti-static materials to prevent component damage

Accurate load calculation and appropriate caster selection form the foundation for safe equipment operation. Comprehensive evaluation of material properties, dimensional requirements, functional types, installation methods, and environmental conditions ensures optimal performance. Proper selection and maintenance extend service life while minimizing costs and safety risks.