1. Materai: Aluminum, Iron, Brass, or other customized requests SUS201,SUS304,SUS316,A2-70,A2-80,A4-80,4.8 6.8 8.8 10.9 12.92. Size: M4-M163. Standard:?DIN GB ISO JIS BA ANSI4. Certification: ISO9001, SGS, CTI, ROHS5.Model: BLFAS-023Q: What is the importance of the screw?A: Screws are indispensable industrial essentials in daily life: such as cameras, glasses, clocks, electronics, etc.; use screws; TV, electrical products, musical instruments, furniture, etc.; for engineering, construction, bridges, use large screws Nuts, traffic appliances, airplanes, trams, cars, etc. are used for both size and size. Screws have an important task in the industry. As long as there is industry on the earth, the function of the screw is always important. http://www.blfspchina.com/screw...-clasp-sealing-bolt.html