1.Steel fiber is a new type material in the construction field 2.It is made of low carbon steel wire and stainless steel 304, 310 3.Wildly used in the tunnerl, bridge, highway, airport road surface, ect for concrete reinforcement. 4.Diameter from 0.4mm to 1.2mm 5.Length 25mm to 60mm 6.Tensile strength >1000 mpa. 20kg/carton.