What are the main types of industrial casters?

Industrial casters are core moving components for industrial equipment, heavy-duty shelving, logistics carts, and more. They must withstand heavy loads and complex working conditions (such as workshop floors and warehouse environments). Their classification is based on three core dimensions: load capacity, mobility characteristics, and structural design. Specifically, they can be divided into the following six categories, with significant differences in their applicable scenarios and performance:

1. Classification by "Mobility and Steering Characteristics": Determines Equipment Flexibility
This is the most basic classification of industrial casters, directly affecting the equipment's steering and positioning capabilities. They are primarily divided into two categories:
Fixed Casters (Steer Casters)
Structural Features: The wheel can only roll in a single direction and has no steering function. They are typically paired with a bracket and fixed axle and cannot rotate horizontally.
Key Advantages: Strong load-bearing stability (the bracket provides more concentrated force), making them suitable for equipment requiring linear motion (such as heavy conveyors and fixed shelf bottoms).
Suitable Applications: Industrial trailers (requiring linear transport along tracks) and large equipment bases (requiring only forward and backward movement, without steering). They are often used in combination with universal casters (for example, a "2 fixed + 2 universal" combination for a balanced balance of stability and flexibility). Swivel Casters
Structural Features: A swivel bracket on top of the wheel (allows 360° horizontal rotation). Some models feature built-in ball bearings or a turntable for low steering resistance.
Core Advantages: Flexible steering allows equipment to be moved in any direction, suitable for confined spaces (such as workshop aisles and warehouse shelving).
Sub-Types:
Ordinary swivel casters: Without brakes, suitable for light-load equipment that requires frequent steering (such as logistics carts and tool carts).
Swivel casters with brakes (double brakes/single brakes): Lock the wheel's rotation (single brake) or simultaneously lock the wheel and steering (double brakes), suitable for temporary fixturing (such as assembly line workbenches and heavy material carts).

2. Classification by "Load Capacity": Matching Different Load Requirements
Industrial loads vary greatly (from tens of kilograms to tens of tons), requiring precise classification by load-bearing grade to avoid overload damage:
Light Industrial Casters
Load Range: Single wheel load ≤ 100 kg, overall equipment load ≤ 400 kg;
Material: Wheels are typically made of polyurethane (PU) or nylon (PA), with brackets made of thin steel (1-2 mm thick) or engineering plastics;
Suitable Applications: Light tool carts (such as workshop maintenance carts), small warehouse racks (for storing light parts), and electronics factory equipment (such as testing instrument bases). Medium-Duty Industrial Casters
Load Range: 100-500kg per wheel, 400-2000kg overall load capacity;
Material Features: Wheel body made of high-hardness polyurethane (Shore D 85-90) and glass-fiber reinforced nylon, bracket made of thickened steel plate (2-4mm thick), axle typically made of galvanized steel or 304 stainless steel;
Suitable Applications: Medium-duty logistics vehicles (such as warehouse cargo transfer vehicles), production line racks, and commercial refrigeration equipment bases. Heavy-Duty Industrial Casters
Load Range: 500-2000kg per wheel, 2000-8000kg overall equipment load.
Material Features: Wheel body is cast iron with a steel-core polyurethane (the steel core provides enhanced load-bearing capacity, while the polyurethane provides anti-slip and quiet operation). Bracket is high-strength steel plate (4-8mm thick, partially welded with reinforcement ribs). Axle is 45# steel or 316 stainless steel (for high bending strength).
Suitable Applications: Heavy-duty racking (such as the bottom of warehouse shelving units), large mold carts (for transferring molds in workshops), and industrial oven bases. Extra-heavy-duty industrial casters
Load range: Single wheel ≥ 2000kg, overall equipment load ≥ 8000kg;
Material features: Wheel body is solid steel or cast iron (impact and crush-resistant), bracket is manganese steel plate (8-15mm thick, hot-forged), axle is alloy structural steel (such as 40Cr, quenched and tempered for enhanced hardness), some are equipped with double bearings for pressure distribution;
Suitable applications: Heavy machinery and equipment (such as machine tools, large compressor bases), port logistics pallet trucks (carrying container parts), and heavy-duty translation platforms in workshops.

3. Classification by Wheel Material: Suitable for Different Working Environments
The wheel material directly determines the caster's wear resistance, corrosion resistance, and floor compatibility. Selection should be based on the floor and media used in the industrial environment:
Nylon (PA) Casters
Core Characteristics: Wear resistance (wear rate ≤ 0.1g/1000 revolutions), resistance to weak acids and alkalis, and strong load-bearing capacity, but poor elasticity (easily brittle at low temperatures);
Suitable Applications: Dry workshops (such as machining workshops with cement floors) and storage environments without corrosive media (such as parts warehouses).
Polyurethane (PU) Casters
Core Characteristics: Good elasticity (vibration dampening, silent operation), anti-slip (friction coefficient ≥ 0.6), and resistance to chemical solvents, but easily softens at high temperatures (performance degrades above 50°C);
Suitable Applications: Electronics workshops (anti-static floors, silent operation required), food processing plants (resistant to cleaning fluids, easy to clean). Cast Iron/Steel Wheel Casters
Core Features: Impact and crush resistance (can withstand heavy impacts), high temperature resistance (stable up to 300°C), but heavy and prone to scratching floors (such as ceramic tiles and epoxy floors).
Suitable Applications: Heavy industrial workshops (such as steel mills and forging workshops with concrete or railroad floors), high-temperature environments (such as equipment near kilns).
Rubber Casters
Core Features: Excellent slip resistance (friction coefficient ≥ 0.7 on wet surfaces) and excellent quietness, but poor wear resistance (lifespan 30% shorter than nylon) and rapid aging.
Suitable Applications: Wet workshops (such as automotive paint shops and car washes), and environments requiring floor protection (such as laboratory epoxy floors).
High-Temperature Casters
Material Features: The wheel body is made of silicone rubber and polytetrafluoroethylene (PTFE), capable of withstanding extreme temperatures from -50°C to 260°C. The bracket is made of high-temperature-resistant stainless steel (310S).
Suitable Applications: Baking workshops (such as automotive paint drying lines) and high-temperature equipment in metallurgical plants (such as material carts near furnaces).

4. Classification by "Special Functions": Meeting the Special Needs of Industrial Scenarios
For special operating conditions such as dust protection, anti-static, and corrosion resistance, industrial casters must have additional features, primarily including:
Anti-static casters
Features: Conductive materials (such as carbon powder or metal fibers) built into the wheel or bracket can conduct static electricity from the equipment to the ground (ground resistance ≤ 10^6Ω), preventing static electricity from igniting flammable and explosive media.
Applicable scenarios: Chemical workshops (storing solvents and gas), electronics factories (producing semiconductors and integrated circuits, where static electricity must be prevented from damaging components).
Dustproof/Anti-Tangle Casters
Features: Sealing caps on the wheel edges prevent dust from entering the bearings, and anti-tangle features on the axle (such as raised ribs to prevent entanglement of thread and metal debris).
Applicable scenarios: Textile factories (highly dusty), flour mills (highly dusty), and machining centers (highly dusty). Corrosion-Resistant Casters
Features: The wheel body is made of polytetrafluoroethylene (PTFE) and 316 stainless steel, and the bracket and axle are also made of 316 stainless steel, resisting corrosion from strong acids, strong alkalis, and salt spray.
Applicable scenarios: Electroplating workshops (strong acid solutions), coastal factories (high salt spray environments), and chemical storage tank bases.

Summary
Industrial caster selection requires "matching to needs": First, determine the equipment load (select light, medium, or heavy) and the required mobility (fixed or universal). Then, consider the working environment (floor material, temperature, and media) to select the wheel body material. Finally, add features based on special needs (anti-static, dustproof). For example, a light turnover cart in an electronics factory should choose a "medium-duty universal polyurethane anti-static caster," while a heavy mold cart in a steel plant should choose an "extra-heavy-duty fixed cast iron caster." This avoids premature caster damage and equipment safety hazards caused by mismatched casters.