The carbon content of carbon spring steel carbon spring steel (mass fraction) is generally 0.62% to 0.90%. In accordance with its manganese content is divided into general manganese content (mass fraction) (0.50% - 0.80%) as 65,70,85 and high manganese content (mass fraction) (0.90 to 1.20%), as 65Mn categories. Alloy spring steel alloy spring steel is based on the carbon steel, through appropriate one or more alloying elements added to improve the mechanical properties of steel, hardenability and other properties to meet the required performance of manufacturing all kinds of spring steel . The basic composition series alloy spring steel have, silico-manganese spring steel, chrome silicon spring steel, chrome-manganese spring steel, chrome vanadium spring steel, tungsten chrome vanadium spring steel. On the basis of these series, there are a number of brands in order to improve certain aspects of their performance and added molybdenum, vanadium or boron and other alloying elements. In addition, from other types of steel, such as high-quality carbon structural steel, carbon tool steel, high speed tool steel, stainless steel, select some grades as spring steel. Classification according to production and processing methods ⒈ hot rolling (forging) hot-rolled steel products including round, square steel, flat steel, steel, forged round bar, square steel. ⒉ cold drawn (rolled) steel including steel wire, steel, cold-drawn material (cold drawn bar). Delivery status classification according ⒈ hot-rolled steel (forged) hot-rolled steel A. (forging) state of delivery of steel thermoformed into spring, followed by quenching and tempering. B. Delivery of steel in the annealed condition is made by cold forming the spring, followed by quenching and tempering. Above shall comply with the appropriate provisions of the delivery status of hardness. ⒉ cold drawn (rolled) steel wire ① A. austempering salt bath of cold drawn steel wire (also known as Padden off the process of cold drawn steel wire) made of spring steel wire after low temperature tempering only to eliminate stress. ② oil quenched and tempered wire cold drawn to the desired size after continuous heating, continuous oil quenching and tempering lead. With just a spring steel wire made after the end of warm fire to eliminate stress. ③ cold-drawn steel wire (ie without quenched and tempered steel) a. In cold-drawn delivery. b. The annealing, normalizing or tempering state delivery. More than two states should be subject to the delivery of steel after quenching and tempering made of spring. B. ① cold rolled strip made of spring after the state of delivery need to be tempering to eliminate stress. ② quenching and tempering state delivery need to be made after spring tempering to slashing stress. ③ fire annealing state delivery need to be made after spring C. quenched and tempered steel cold-drawn steel in the annealed state delivery is made by cold forming the spring, followed by quenching and tempering. Other classifications addition to the above, there are other classifications, such as: delivery conditions according to different requirements can be classified according to chemical composition (mechanical properties) delivery and delivery by hardenability. Press the spring working conditions can be divided into static load spring steel, spring steel to withstand impact loads, high (low) temperature corrosion-resistant spring and spring steel.