According to EN50483 standard,
- Strong PA66 cover with 1.5 times torque force testing without problem.- High hardness Al alloy or Cu teeth with tin plated.
- Stable shear head force keep ± 2Nm.
- Same hardness of nut and bolt thread,prevent from thread broken.
- UV protected plastic.
- Hot dip,dacromet or chroming galvanization,prevent from oxidation and corrosion.
- Some type can be used for underwater of 6kv withstand voltage,and compact structure of PVC or rubber
lining with teeth and body to prevent from leakage.