11. Welding steel before its steel preceded by the letter "H", to distinguish it from other types of steel. Such as stainless steel wire for the "H2Cr13" fine tooth stainless steel screws can be used to distinguish between stainless steel "2Cr13". 12. Electrical letters and numbers ① with silicon steel. DR represents the letter head of steel hot-rolled silicon steel electrician, DW represents electrician cold-rolled non-oriented silicon steel, DQ represents electrician cold-rolled silicon steel. Digital ② letter, said after the iron loss value (W / kg) 100 times. Stainless steel screws, stainless steel nuts, stainless steel rivets, stainless steel bolts, screws ③ tail 316L steel letters "G" by Yantai fine tooth stainless steel screws, expressed at a high frequency test; do not add "G" by Heze fine tooth stainless steel screws, He expressed at a frequency of 50 cycles under test. Such as steel DW470 represents electrical products cold rolled non-oriented silicon steel at 50 Hz frequency of maximum unit weight of iron loss is 4.7W / kg. SJ 2830-1987 television receivers fastener screw cross recessed large spherical flange SJ 2831-1987 television receiver with large spherical head cross recessed fasteners self-tapping locking screw fasteners SJ 2832-1987 TV receivers cross recessed large spherical flange screws - SJ 2833-1987 television receivers Cross recessed tapping fastener locking screw technology conditions SJ 2834-1987 television receivers fastener Cross recessed pan headband flat washer SJ 2835-1987 combination screw combination screw fastener television receivers Cross recessed pan headband spring washer 304 stainless steel screws 316 stainless steel welded stainless steel rivet nut screw 316, 316 stainless steel hose clamps 316 stainless steel inside and outside the large flat head screw Gasket . Stainless steel adapter, stainless steel expansion bolt 304 stainless steel eyebolts Heze fine screw | Jinan Road ground (certified) | stainless steel fine screw is provided by Jinan Daoqin Trading Company. Jinan Daoqin Trading Company (www.daoqinshangmao.com) (www.daoqinshangmao.com) Shandong Jinan, hardware accessories leader over the years, the company implement the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer demand. Jinan Road ground in leadership with the staff warmly welcome all inquiries negotiations to create the Jinan Daoqin better future.