③ vanadium steel V, Ti Ti, Al Al, boron B, rare earth RE alloying elements are micro-alloying elements, although very low levels, should bid out in steel. For example 20MnVB steel. 0.07-0.12% vanadium locking locking screw, boron is 0.001 to 0.005%. ④ High quality steel should finally add "A" in the steel, as distinct from the general high quality steel. Alloy structural steel ⑤ special purpose Zaozhuang locking locking screw, steel dubbed (or suffix) symbols for use in the steel. For example, riveting Lo 30CrMnSi special steel, steel, said as ML30CrMnSi. 7. Spring steel spring steel can be divided according to the chemical composition of carbon spring steel and alloy spring steel two categories, its steel representation, the former is basically the same high-quality carbon structural steel, alloy structural steel which is basically the same. 8. Rolling steel ① preceded by the letter "G" in Dongying locking locking screw, represents Rolling steel type. Stainless steel bolts, screws 304, 316 carbon content of carbon chromium bearing steel screws ② steel is not marked, the chromium content of a few thousandths. For example GCr15. Steel representation carburizing bearing steel, structural steel and alloys basically the same. Qingdao locking locking screws | lock locking screws | Jinan Road ground is provided by Jinan Daoqin Trading Company. Jinan Daoqin Trading Company (www.daoqinshangmao.com) (www.daoqinshangmao.com) strong, credible, in Jinan, Shandong hardware accessories industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead Jinan Road ground into the brilliant and you work for a better future!