... 2. Standard: GB3639, ASTM A519, DIN17175, EN 10305 Precision Seamless Steel Pipe1. Material: 10, 20, 45, Q345, JIS STKM 13C, DIN ... , Agriculture machine, Machinery, Furniture: gas spring, Exercise equipments, Medical equipments, Door closer, Condensing unit Pipe 10. Certificate Standard: ISO 9001: 200011 ...