... 1) chinese manufacturer. 2) high quality with competitive prices nylon insert lock nut , ASME NE NTE , din ... Physical performance:a) class 2, made from low carbon steel, C1008, C1010, Q195 etcb) class 5, class ... 8, made from high carbon steel such as C1035, C1045, etc, And with ... hardened treatment.c) stainless steel SS304 SS316.-3)Surface treatment:plain/self colour, ...