... ST 52 2. Standard: GB3639, ASTM A519, DIN17175, EN 10305 Precision Seamless Steel Pipe1. Material: 10, 20, 45, Q345, JIS STKM 13C, DIN ... . Protection: plastic cap9. Applications: Hydraulic cylinder, Pneumatic cylinder, Precise machine pipes, Agriculture machine, Machinery, Furniture: gas spring, Exercise equipments, Medical equipments ...