1. Shackle should be smooth, cracks and other defects are not allowed, sharp edges, combustion.
2. Cast iron or cast iron shackles prohibited. The buckle can be made of steel forgings and axle pin bars processed after forging.
3. No drilling or welding repair . Permanent deformation after the button and needle should not be repaired.
4. When using, the latches and fasteners should be checked without excessive wear, deformation and fatigue cracks.
5. when using the horizontal spacing must not pull the needle must be inserted into the needle.
6. use shall not exceed the safety load