JB / T 4213-1996 fasteners cold heading die technical conditions Beijing Institute of Electrical and JB / T 7384.13-1994 fasteners self-tapping locking screw a circumscribed circle diameter gauge JB / T 7384.14-1994 wood screw threaded fastener trails caliper JB / T 7384.2-1994 fasteners countersunk head and countersunk head height test mode JB / T thickness test mode JB 7384.3-1994 fastener head and grooved support surface height between the / T 7384.4-1994 fastening member wrenching height test mode JB / T 7384.7-1994 Fasteners slot width plug JB / T 7384.8-1994 slotted fastener depth plug gauge 304 stainless steel self drilling screws, 304 stainless steel hose clamps 9. Alloy tool steel and high speed tool steel alloy tool steel ① steel average carbon content is ≥1.0% Heze drop-resistant screw screw, the carbon content is not marked; when the average carbon content of <1.0%, to a few thousandths. For example Cr12, CrWMn, 9SiCr, 3Cr2W8V. ② steel alloying element content representation, basically the same as alloy structural steel. But for low chromium steel alloy tool steel, the chromium content of a few thousandths of Yantai drop-resistant screw screw and represents the digital content before the "0", so that it and the general element content by percentage Methods few that are distinguished. For example Cr06. ③ high-speed steel, tool steel carbon content is generally not marked drop-resistant screw screw, marked only a few percent of the average content of various alloying elements. Such as steel, tungsten high speed steel is expressed as "W18Cr4V". Steel numbers preceded by the letter "C" who indicated that their carbon content higher than the highest "C" common steel. Liaocheng drop-resistant stainless steel screws screws screws, screw 316 stainless steel bolts, stainless steel rivets, stainless steel rivet nut. Yantai drop-resistant screw screw, Jinan Road ground (online consultation), drop-resistant screw screws 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.