Caster load capacity is a crucial factor when choosing hand trucks. This article guides you on how to calculate caster load capacity to ensure safe and efficient usage.
Maximum Load Capacity vs. Optimal Load Capacity
Manufacturers typically specify two types of load capacities: maximum and optimal.
- Maximum Load Capacity: The highest load a caster can withstand without immediate failure.
- Optimal Load Capacity: The load that allows the caster to operate smoothly, durably, and extend its lifespan.
Maximum load capacity is for reference only and doesn’t reflect actual quality. Calculating caster load capacity should be based on the optimal load for long-term efficiency.
Determining Optimal Load Capacity
To determine optimal load capacity, manufacturers conduct load tests according to EU standards combined with rollability tests. This load capacity applies in ideal working conditions:
- Flat and even floor surface.
- Operating temperature between 68 – 86°F (20 – 30°C).
- Movement speed not exceeding 2.5 mph (4 km/h).
If your working environment meets these 3 criteria, simply choose casters with a load capacity greater than the load you need to carry.
Calculating Load Capacity for Uneven Floors
For uneven and rough floors, the actual load capacity of casters will be lower than the theoretical load capacity. The method for calculating caster load capacity in this case is as follows:
X = (A + B) / (n – 1)
- X: Minimum load each caster must bear.
- A: Weight of the hand truck frame.
- B: Weight of the load to be carried (maximum possible).
- n: Number of casters used.
Why divide by (n-1)? Theoretically, the load is evenly distributed across each caster. However, in reality, situations can occur where:
- Goods are not evenly loaded.
- Casters do not make even contact with the floor.
- Casters move on rough surfaces, experiencing additional external forces from impacts.
Impact of Load Weight and Speed
Load weight and movement speed significantly affect caster durability. Overloading or excessive speed will reduce the actual load capacity.
Impact Level Comparison Table:
| Load Weight (kg/caster) | Movement Speed (km/h) | Remaining Load Capacity (%) |
|---|---|---|
| ≤ 4 | ≤ 4 | 100 |
| 4 – 6 | 4 – 6 | 85 |
| 6 – 8 | 6 – 8 | 70 |
| ≥ 200 | ≤ 4 | 100 |
| ≥ 200 | 4 – 6 | 80 |
| ≥ 200 | 6 – 8 | 60 |
High speed on uneven floors will cause vibrations, increase friction, and reduce caster lifespan. Recommended movement speed for hand trucks is 1.2 – 3 mph (2 – 5 km/h).
Impact of Temperature
In harsh temperature environments, choose specialized heat-resistant casters and move them on flat surfaces at speeds not exceeding 2.5 mph (4 km/h).
Conclusion
Calculating caster load capacity correctly is crucial for ensuring safety and efficient usage. Consider factors like optimal load capacity, floor surface, speed, and temperature to choose the right casters. Hopefully, this article has provided you with a precise method for calculating caster load capacity.
