Production: according to wire diameter is divided into 0.4-0.6mm, divided by the mechanical properties of B, C grade. 
 Performance indicators: 
 1. Mechanical properties meet the GB4357-89B level, C level of tensile strength; 
 2. Technology to reverse the performance meets the GB4357-89B level, C level to reverse the number of times; 
 3. Winding process performance in line with GB4357-89B level, C-level requirements; 
 4. Using high quality carbon steel wire rods, and its P content ≤ 0.030%, sulfur content ≤ 0.020%; 
 5. Zinc coating uniform, continuous, solid, smooth; 
 6. In full compliance with GB/T4357-89 standards. 
 Uses: used in the manufacture of various springs.