Thicker oil quenching tempering spring steel wire: Black annealed wire material is generally composed of Q195 wire rod drawing model into the black iron wire. Selected raw materials by around 1000 ° after high temperature calcinations to keep enough time, and then cooling at appropriate rate. The purpose is to reduce the hardness and improve cutting machining; Eliminate the residual stress, stable size, reduce the deformation and crack tendency; Fine grains, adjust, eliminate defects.