1, the shackle should be smooth, not allowed to have cracks, such as defects, sharp edges, burning.
2, a ban on the use of cast iron or cast iron shackles. The buckle can be made of steel forgings, forged and machined shaft pins.
3, should not be tied to any drilling or welding repair. buttons and pins should not be repaired after a permanent warp.
4, when used, should check the buckle and latch, not excessive wear, deformation and fatigue crack.
5, the needle must be inserted when using horizontal spacing must not be drawn.
6, after the correct installation, the buckle width axis should not lower the body, the thread connection is very good.
7, the use must not exceed the safety load yoke.