Characteristics of high-quality carbon structural steel (GB / T699-1999) have good ductility and adequate strength, better process performance, welding performance is acceptable, mostly used in normalizing the status of state and neuromodulators. The purpose of this steel is widely used in the manufacture of various forgings and hot items, cold-drawn and forging steel, seamless steel tubes, machinery manufacturing parts, such as crankshafts, shafts, shaft pins, levers, connecting rods, beams, sleeves, wheels, washers and screws, nuts, motorcycle racks. . Heat treatment and microstructure specifications: Heat treatment specifications: normalizing, 870 ℃; quenching, 850 ℃; tempering, 600 ℃. Microstructure: ferrite and pearlite. Delivery status: to heat or no heat treatment (annealing, normalizing or tempering) state delivery. Require heat treatment delivery should be specified in the contract, no heat treatment is not indicated by delivery.