Black annealed wire Before the big pull, there will be a surface treatment: Pickling----Washing----Phosphide-----Soaping----Drying. The treatment function is rust removing, Phosphide and soaping are good for next pulling proess. Row material Low carbon steel wire , Q195 or Q235 Advantages Soften and flexible character Low costs and economy Easy to handle or install Tensile strength :300-500Mpa Rate of Extend :15%