1、 Core testing items

1Durability testing:‌

• ‌Open close cycle testSimulate the daily use of the lock buckle and perform 20000 opening and closing operations under rated load. After testing, the lock buckle should have no fracture, deformation, or functional failure.

• ‌Fatigue strength testApply longitudinal or transverse dynamic loads to the lock buckle through reciprocating motion equipment (such as fatigue testing machine), with a frequency of usually 30 cycles per minute, and record the number of cycles before the lock buckle fails.

2. Mechanical performance testing‌

• ‌Tensile/compressive strengthApply static tension or pressure to the lock buckle using a universal material testing machine until it fractures or deforms, and record the maximum load value.

• ‌Impact resistance testApply 2.6J of impact energy to the lock buckle through a drop hammer impact testing machine to verify its resistance to deformation or cracking.

1. 2.1Anti pry performance test‌

• Apply an external pressure of 200N (mechanical or tool pry) to the lock buckle, test its anti pry ability, and ensure that the lock maintains its function even under violent damage.

2. 2.2Corrosion resistance test‌

• Simulate the corrosion resistance of the lock buckle in high salt and high humidity environments through salt spray test or wet heat test, and observe whether the surface coating falls off or rusts.

2、 Testing process

1. 1preliminary preparation‌

• ‌Sample selectionRandomly select lock buckle samples to ensure representativeness and consistency.

• ‌Equipment CalibrationVerify the load sensor, counter, and temperature and humidity control system of the testing machine to ensure data accuracy.

2. 2Environmental condition setting‌

• Set the temperature and humidity according to standard requirements (such as 23 ± 2 ℃, 60 ± 2% humidity), and maintain a stable testing environment.

3. 3. Perform testing‌

• ‌Staged loadingFirstly, conduct a low load pre-test (such as 10% rated load), and then gradually increase it to the standard load for formal testing.

• ‌real-time monitoringRecord the stress changes, displacement data, and abnormal phenomena (such as abnormal noise and jamming) of the lock buckle during testing through sensors.

4. 4. Post test evaluation‌

• ‌Functional examinationAfter the test is completed, manually operate the lock buckle to verify the smoothness of opening and closing and whether the self-locking function is normal.

• ‌Appearance and size inspectionUse tools such as feeler gauges and microscopes to inspect the surface scratches, deformation, and key dimensional deviations of the lock buckle (such as gaps ≤ 2mm).

3、 Reference standards and judgment criteria

1. ‌industry standard‌

• ‌QB/T 2171-2014Specify the core indicators such as fatigue strength and opening and closing life of the lock buckle.

• ‌QB/T 2922-2007Clarify the testing methods for the anti pry performance and impact resistance of locks.

• ‌GB 20400Environmental and safety requirements (such as heavy metal content limits) for materials such as leather and metal.

2. ‌criterion‌

• No functional failure (such as inability to lock, spring breakage).

• There is no obvious damage to the appearance (coating detachment ≤ 5%, no structural cracks).

• Size change rate ≤ 3% (compared to initial value).

• The lock buckle must meet the following requirements after testing:

4、 Equipment and Tools

1. ‌main equipment‌

• Fatigue testing machine (supporting dynamic loading and cycle counting).

• Salt spray test chamber (compliant with ASTM B117 standard).

• Universal material testing machine (with a range covering 0-1000N).

• Luggage clip durability testing machine（QB/1333-2018, QB/T 5247-2018 and other standards)

• Luggage magnetic buckle fatigue resistance testing machine（QB/T1333-2018, QB/T 5084-2017 and other standards)

2. ‌auxiliary tool‌

• Digital micrometer (accuracy 0.01mm).

• Spring scale or electronic dynamometer (calibration cycle ≤ 6 months).