It is high strength medium carbon steel, cold plastic deformation is low, poor welding performance and hardenability, but no temper brittleness, cutting performance is acceptable. usually in normalizing, hardening, tempering used for the manufacture of high wear resistance, mechanical machining parts and spring parts with small dynamic load and impact, such as Forging of gear, shaft, rod, roller, friction disc, agricultural digging ploughshare, heavy-duty spindle.