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Fatigue testing of chain hoists: revealing the key processes and importance behind them
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Fatigue testing of chain hoists: revealing the key processes and importance behind them

2025-05-30

Fatigue testing of Chain Hoists: revealing the key processes and importance behind them
In the industrial field, chain hoists are common lifting equipment, and their quality and reliability are directly related to the safety and efficiency of operations. For international wholesale buyers, it is crucial to understand the fatigue testing of chain hoists, because this not only helps you choose high-quality and reliable products, but also ensures smooth business operations and reduces the risks and losses caused by equipment failures. This article will explore the fatigue testing of chain hoists in depth and take you to learn more about this key process.

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1. The importance of fatigue testing
During the use of chain hoists, they will be subjected to repeated tension and pressure for a long time, and fatigue phenomena such as chain elongation, component wear, and structural deformation will easily occur, which will seriously affect their performance and safety. Fatigue testing simulates repeated loads under actual working conditions to detect potential fatigue problems of chain hoists in advance and ensure their stability and reliability in long-term use. This not only helps to ensure operational safety and avoid accidents caused by equipment failure, but also extends the service life of the equipment, reduces maintenance costs, and improves production efficiency. For international wholesale buyers, choosing hand chain hoists that have passed strict fatigue testing means laying a solid quality foundation for your business and enhancing your market competitiveness.

2. Standards and basis for fatigue testing
International standards: For example, the ISO 9001 quality management system standard puts forward comprehensive requirements for the production process and quality control of hand chain hoists, including relevant provisions for fatigue testing. In addition, there are also international standards specifically for lifting equipment, such as ISO 4307, which clarify the fatigue test methods, load requirements and qualified standards of hand chain hoists. These standards are widely used and recognized worldwide, providing unified specifications for the production and testing of hand chain hoists.
National standards: Each country also has corresponding national standards. For example, China's "GB/T 20652-2021" clearly stipulates that hand chain hoists must pass the three core links of load testing, fatigue testing and environmental adaptability testing to ensure that their tensile strength, wear resistance and corrosion resistance meet the requirements.

3. Equipment and tools for fatigue testing
Fatigue testing machine: This is the core equipment for fatigue testing of hand chain hoists, which can simulate the repeated lifting and pulling force changes of hand chain hoists in actual use. It is usually composed of a drive system, a transmission system, a loading system and a control system. The drive system provides power, and the transmission system transmits the power to the loading system to simulate the movement of the chain or hand chain of the hand chain hoist. The loading system applies corresponding tension to the hand chain hoist according to the set load requirements. The control system can accurately control the test parameters, such as load size, loading frequency, number of cycles, etc., and can monitor and record test data in real time.
Sensors and measuring instruments: During the test, various sensors and measuring instruments are needed to monitor the stress, deformation and performance changes of the hand chain hoist. For example, the tension sensor is installed on the loading system of the testing machine to accurately measure the tension applied to the hand chain hoist and feed the data back to the control system in real time. The displacement sensor is used to measure the displacement of the chain or hook of the hand chain hoist under load to evaluate its deformation. In addition, strain gauges and other measuring tools may be used and pasted on the surface of key components of the hand chain hoist to measure the strain of the material and further analyze its fatigue performance.
Data acquisition and analysis system: This system is connected to equipment such as fatigue testing machines and sensors to collect, store and analyze a large amount of data generated during the test. Through the data acquisition system, the signal from the sensor can be converted into a digital signal and stored in the computer. Then, professional data analysis software is used to process and analyze the data, and load-displacement curves, strain-cycle number curves, etc. are drawn to intuitively show the performance of the hand chain hoist in the fatigue test and help technicians determine whether it meets the standards and requirements of the fatigue test.

4. Specific process of fatigue test
Preparation
Appearance inspection: Before starting the fatigue test, a comprehensive appearance inspection of the hand chain hoist to be tested is first required. Check whether there are obvious defects on its surface, such as cracks, deformation, scratches, etc. These defects may affect the performance of the hand chain hoist in the fatigue test and even lead to inaccurate test results. At the same time, it is also necessary to check whether the various parts of the hand chain hoist are complete and whether the connection is firm, such as hooks, chains, hand chains, gears, etc., to ensure that they are in a good initial state.
Loading device setting: According to the rated load and test requirements of the hand chain hoist, adjust the loading device of the fatigue testing machine. Install the hand chain hoist correctly on the testing machine to ensure that its connection with the testing machine is reliable and can withstand the tension during the test. At the same time, set the position and parameters of measuring instruments such as tension sensors and displacement sensors so that they can accurately measure the force and deformation of the hand chain hoist during the test.
Parameter setting: Set the parameters of the fatigue test according to relevant test standards and specifications. It mainly includes the size of the loading load, which is usually a certain proportion of the rated load of the hand chain hoist, such as 1.25 times the rated load, etc.; the loading frequency, that is, the number of lifting cycles per minute, is generally determined according to the actual use conditions and test purposes of the hand chain hoist; the number of cycles is set according to the test requirements and standard regulations, generally not less than 10,000 cycles, to fully evaluate the fatigue performance of the hand chain hoist.
Test process
Initial loading: Start the fatigue testing machine and perform initial loading on the chain hoist according to the set parameters. Gradually increase the tension to the set loading load, observe the force response of the chain hoist and the working status of each component, and ensure that there is no abnormality under the initial loading.
Cyclic loading: After the initial loading is completed, cyclic loading begins. The fatigue testing machine repeatedly lifts and lowers the chain hoist according to the set frequency and load to simulate its working cycle in actual use. In each cycle, the chain of the chain hoist is pulled up to the set height, then slowly released and returned to the initial position, and so on. During the cyclic loading process, pay close attention to the changes in various performance indicators of the chain hoist, such as the elongation of the chain, the deformation of the hook, the meshing condition of the gear, the performance of the brake, etc. At the same time, the data acquisition and analysis system monitors and records the tension, displacement, strain and other data in real time for subsequent analysis and evaluation.
Stop inspection: During the fatigue test, the test machine is stopped for shutdown inspection at a certain interval or time. Check whether the appearance of the chain hoist is obviously damaged or deformed, check whether the connection of key components is loose, and measure whether the elongation of the chain exceeds the specified standard (usually 3%). If any abnormality is found, the test should be stopped immediately, the chain hoist should be inspected and analyzed in detail, the cause of the problem should be found out and corresponding measures should be taken.
Fault handling: If the chain hoist is stuck or slipped during the test, the shutdown protection unit of the test machine will start immediately, stop loading and protect the safety of the equipment and testers. At this time, it is necessary to carefully analyze the cause of the fault, such as whether it is caused by excessive chain wear, gear jamming, and debris entering. According to the cause of the fault, take corresponding treatment measures, such as replacing worn parts, cleaning debris, adjusting lubrication, etc. After troubleshooting, retest to ensure the accuracy and reliability of the test results.
Test result evaluation
Data analysis: After the test is completed, the collected data will be sorted and analyzed. Draw the load-displacement curve to observe the change of stiffness of the chain hoist during cyclic loading; draw the strain-cycle number curve to evaluate the degree of fatigue damage of the material. By analyzing these data, we can understand the performance of the hand chain hoist in the fatigue test and determine whether it has signs of fatigue failure, such as plastic deformation, crack initiation and expansion.
Performance evaluation: According to the results of data analysis, combined with relevant standards and specifications, the fatigue performance of the hand chain hoist is evaluated. The main evaluation indicators include the elongation of the chain, the deformation of the components, the occurrence of fatigue cracks, etc. If all performance indicators of the hand chain hoist meet the standard requirements and no fatigue failure occurs within the specified number of cycles, it is judged that it has passed the fatigue test and has good fatigue performance and reliability. On the contrary, if any indicator does not meet the standard requirements, the hand chain hoist fatigue test is judged to be unqualified, and further analysis of the reasons and improvements are required.
Report preparation: Finally, according to the process and result evaluation of the fatigue test, a detailed fatigue test report is prepared. The report content should include the basic information of the hand chain hoist, the purpose of the test, the test equipment and tools, the test parameter settings, the test process records, the data analysis results, the performance evaluation conclusions, etc. The test report should be objective, accurate and complete, and can clearly reflect the fatigue test of the hand chain hoist, providing a good decision-making basis for buyers and users.

5. Factors affecting fatigue test results
Test load: The size of the test load directly affects the results of the fatigue test. If the load is too large, the hand chain hoist may fail prematurely during the test; if the load is too small, it cannot truly reflect its fatigue performance in actual use. Therefore, it is very important to accurately set the test load, and it should be reasonably selected according to the rated load and actual use conditions of the hand chain hoist in accordance with relevant standards.
Loading frequency: The loading frequency will also affect the results of the fatigue test. A higher loading frequency will cause the hand chain hoist to withstand more cyclic loading times in a shorter period of time, accelerating the development of its fatigue damage. However, too high a loading frequency may cause the temperature of the testing machine and the hand chain hoist to rise, thereby affecting the accuracy of the test results. Therefore, it is necessary to select a suitable loading frequency based on the characteristics of the hand chain hoist and the purpose of the test, usually between 10-60 times/minute.
Environmental factors: Environmental factors such as temperature, humidity, dust, etc. will also affect the fatigue test results of hand chain hoists. For example, in a high temperature environment, the material properties of the hand chain hoist may change, resulting in a decrease in its fatigue strength; in a humid or dusty environment, it is easy to cause corrosion and wear of the components, accelerating the occurrence of fatigue failure. Therefore, when conducting fatigue tests, the environmental conditions should be controlled as much as possible to keep the test environment clean, dry and constant temperature to reduce the impact of environmental factors on the test results.

6. How to ensure the effectiveness of fatigue testing
Choosing a suitable testing agency: For international wholesale buyers, it is crucial to choose a testing agency with professional qualifications and rich experience to conduct fatigue testing. Professional testing agencies should have advanced testing equipment, professional technical teams and a complete quality management system, and be able to conduct fatigue tests in strict accordance with relevant standards and specifications, and provide accurate and reliable test results and reports. When choosing a testing agency, you can check its qualification certification, the accuracy and performance of the testing equipment, and customer evaluation information to ensure that it has sufficient capabilities and credibility.
Strictly follow the test standards: Whether it is a testing organization or a manufacturer, when conducting fatigue tests on Hand Hoists, they must strictly follow the relevant international standards, national standards or industry standards. These standards specify the methods, steps, parameter requirements and qualification standards for fatigue testing, and are important bases for ensuring the effectiveness of the test. Strictly following the standards for testing can ensure the standardization of the test process and the comparability of the test results, making the test results authoritative and credible.
Strengthen the monitoring of the test process: During the fatigue test process, process monitoring should be strengthened to ensure that every link of the test meets the requirements. This includes real-time monitoring of the operating status of the test equipment to ensure its normal operation; strict control of the test parameters to avoid deviations; timely collection and analysis of test data, timely detection of abnormal conditions and taking corresponding measures. At the same time, test records should be kept, and various information during the test process should be recorded in detail so that they can be traced and analyzed when necessary.
Regularly maintain the test equipment: The performance and accuracy of the fatigue test equipment directly affect the accuracy of the test results. Therefore, it is very necessary to regularly maintain and calibrate the test equipment. Regularly maintain the testing machine, clean the dust, oil and other impurities on the surface and inside of the equipment, check whether the parts of the equipment are worn or damaged, and replace and repair them in time. At the same time, regularly calibrate sensors, measuring instruments, etc. to ensure that their measurement accuracy meets the requirements. By regularly maintaining the test equipment, it can be ensured that it is always in good working condition, thereby improving the effectiveness of fatigue testing.

7. Conclusion
The fatigue test of the hand chain hoist is a key link to ensure its quality and safety. For international wholesale buyers, understanding the methods, processes and importance of fatigue testing will help you make wise decisions during the procurement process and choose hand chain hoists with reliable performance and stable quality. This can not only reduce the risk of equipment failure during use and ensure the smooth progress of your business, but also enhance your competitiveness in the market and win the trust and satisfaction of customers. In actual procurement, it is recommended that you choose manufacturers and brands that have passed strict fatigue test certification, and pay attention to the integrity and authority of the test report to ensure that the purchased hand chain hoist can meet your business needs and safety requirements.