1. Scope of Application

This standard applies to caster products used in various industrial production, warehousing and logistics, and equipment handling fields, including but not limited to hand truck casters, shelf casters, and equipment moving casters.

2. Structure and Dimensions

2.1 Structure

Casters are mainly composed of three core components: the wheel hub, bearings, and wheel. The wheel hub is the key component connecting the wheel and the load-bearing device, usually made of metal, with high strength and stability; the bearing is the core moving part of the caster, responsible for supporting the relative rotation of the wheel hub and the wheel, and its performance directly affects the smooth operation and service life of the caster; the wheel is the part that directly contacts the ground, and its material and shape have an important impact on the wear resistance and rolling resistance of the caster.

2.2 Dimensions

Different models of casters have different dimensions. Specific dimensional parameters should be designed and determined according to actual needs and application scenarios. The dimensional parameters of casters mainly include wheel diameter, wheel width, hub height, and shaft hole diameter. The wheel diameter determines the rolling diameter of the caster, affecting its load-carrying capacity and rolling speed; the wheel width is closely related to the stability of the caster; the hub height and shaft hole diameter must match the installation structure of the load-bearing device. Detailed dimensional data should refer to the caster model table, which should clearly list the size range and tolerance requirements of each model of caster to ensure the interchangeability and compatibility of the casters.

3. Materials

The selection of the main material of the caster should be comprehensively considered based on the usage environment and performance requirements. Common materials include cast iron, polished steel, steel plate, and stainless steel. Cast iron material has high strength and wear resistance and is suitable for occasions with large loads and harsh usage environments; polished steel material has a smooth surface, good corrosion resistance, and aesthetics, suitable for places with high environmental requirements; steel plate material has high toughness and processing performance and can meet different usage needs through different processing technologies; stainless steel material has excellent corrosion resistance and is suitable for special environments such as humid and chemically corrosive environments. In addition, the wheel part can also use non-metallic materials such as polyurethane, nylon, and rubber to meet different requirements for wear resistance, elasticity, and noise reduction.

4. Performance Requirements

4.1 Operational Stability

The bearing structure inside the wheel hub should be reasonably designed to ensure that the caster runs smoothly without obvious shaking or jamming. The rotational friction coefficient of the caster is an important indicator for measuring its rolling resistance and should be below 0.11. The specific testing method can use a standard rolling resistance testing device to measure the rolling resistance of the caster under a certain load and speed and calculate the friction coefficient. During the test, the environmental temperature and humidity should be controlled to ensure the accuracy of the test results.

4.2 Load Capacity

The load capacity of the caster is one of its core performance indicators and should meet the load requirements in actual use. Different models of casters should clearly indicate their maximum load capacity according to their size, material, and structural design and mark it in the caster model table. The load capacity test can use a combination of static load test and dynamic load test. The static load test is to install the caster on the test device, gradually apply the load until the design maximum load is reached, and observe the deformation and damage of the caster; the dynamic load test simulates the movement state in actual use, applies periodic load to the caster, and tests its load-bearing performance and fatigue life under dynamic conditions.

4.3 Wear Resistance

The service life of the caster is closely related to its wear resistance and should meet the specified requirements. The wear resistance test can use a wear testing machine to simulate the wear conditions of the caster in actual use and measure the wear amount and wear rate of the wheel. Specific test conditions should be set according to the usage environment and material characteristics of the caster, such as ground material, load size, and running speed. The test results should meet the design service life requirements of the caster, generally with the wear amount not exceeding a certain percentage (such as 10%) of the wheel thickness as the acceptance standard.

4.4 Impact Resistance

The caster may be impacted during use, so it should have sufficient impact resistance. The impact test can use a standard impact testing device to apply an impact of a certain energy to the caster and observe the deformation and damage of the wheel. After the impact, the wheel should not have obvious deformation or cracking and should still maintain normal operation. The setting of the impact energy should be reasonably determined according to the actual usage environment of the caster and the possible impact degree.

5. Inspection and Testing

5.1 Incoming Inspection

The quality inspection department should conduct strict incoming inspection of all incoming casters to ensure that their quality meets the standard requirements.

Appearance quality inspection: Check whether there are cracks, pinholes, pores, scratches, etc., on the surface of the caster, whether the surface coating is uniform and free of peeling, and whether the markings are clear and complete.

Dimensional inspection: Use precision measuring instruments to measure the wheel diameter, wheel width, hub height, shaft hole diameter, etc., of the caster to check whether they are within the specified dimensional tolerances.

Material testing: Use spectral analysis, chemical analysis, etc., to test the main material of the caster to verify whether the material meets the design requirements.

Electrical inspection (if applicable): For casters with electrical components (such as electric casters), their electrical performance should be checked, including insulation resistance, withstand voltage strength, and conductivity, to ensure that they meet relevant electrical safety standards.

5.2 Outgoing Inspection

The quality inspection department should conduct outgoing inspection of all outgoing casters to ensure that their quality is qualified and their performance is stable.

Appearance quality inspection: Same as incoming inspection, re-check the appearance quality of the caster to ensure that no new defects have occurred during production.

Dimensional inspection: Re-check the dimensions of the caster to ensure that the dimensional accuracy meets the requirements.

Load inspection: Use a standard load testing device to conduct a maximum load test on the caster to check its load-carrying capacity and deformation, ensuring that it meets the design requirements.

Durability testing: This includes tests for wear resistance, corrosion resistance, and aging resistance. Wear resistance can be quickly tested using a wear testing machine; corrosion resistance can be tested using salt spray tests, chemical corrosion tests, etc.; and aging resistance can be evaluated through accelerated aging tests such as high-temperature and ultraviolet irradiation.

6. Marking Requirements

The marking of casters is an important carrier of product information and should be clear, accurate, and easy to identify. The following information should be marked on the exterior of the caster:

Manufacturer's Name: Clearly indicate the full or abbreviated name of the manufacturer to allow users to trace the product's origin.

Caster Model: Clearly mark the caster's model number. The model number should be unique and traceable, reflecting the caster's main parameters and performance characteristics.

Quality Standard Mark: Indicate the quality standard number that the caster conforms to, such as this standard number or other relevant industry standard numbers, showing that the product meets the corresponding quality requirements.

Other Necessary Markings: Information such as load capacity, applicable environment, production date, shelf life, etc., can be marked according to the actual situation to facilitate correct use and maintenance of the caster.