1. a good pinch mechanism further terminals have a reliable positioning devices, terminals use, typically generate a lot of torque, ensure there is sufficient contact pressure wire, standard GB2099 and GB16915 clearly stated, when tightening or when loosen the clamp screw, does not cause the terminal itself loose.
　　2. screw-type terminals, self-locking screw ability play a decisive factor, the general principle is based on the self-locking screw terminals "lift tube principle" as the basis. When tightening the screws, the screws tightening force is not directly applied to the wire, but acting on the clamping member, automatic step so that the resulting self-locking thread friction gradually increased, to achieve self-locking screws, will eventually lead clamp on busbars.
　　3. different thread diameter have different torque requirements, such as pressure line M3 screws 80N torque requirements for the terminal will not produce damaging effects.