The inspection steps before the shipment of key locking thread inserts typically include the following key aspects to ensure that their dimensional accuracy, mechanical properties, and assembly reliability meet the standard requirements:
Visual Inspection
Check the surface of the pin thread insert for any cracks, burrs, rust, or other obvious defects, usually conducted through visual inspection for 100% of the products.
Dimensional Inspection
Use tools such as vernier calipers, thread plug gauges, and go/no-go gauges to inspect key dimensions, including outer diameter, inner diameter, pitch, and length, to ensure compliance with design drawings and technical requirements. For example, the deviation of the pin thickness should be controlled within ±0.1mm.
Thread Inspection
Use thread plug gauges to check the go/no-go condition of the internal threads, ensuring that the threads meet the standards and avoiding assembly difficulties or looseness.
Pin and Hole Fit Inspection
Adopt pin insertion testing to verify whether the pin can be smoothly inserted and fit tightly. The guiding section and the inspection section must meet the clearance fit requirements.
Pull-out Resistance Test
Conduct a pull-out resistance test on the pin connection area to ensure that its pull-out resistance is not less than 3kN, usually performed through hammer impact self-locking for sampling inspection.
Material and Property Inspection (if required)
Perform spectral analysis on the material to confirm whether the content of alloying elements meets the requirements for high strength and corrosion resistance