Engineering, mechanical steel pipe Mechanics and Structure tube/Pipe Standard: EN10210 - Non-alloy and fine grain structure steel thermoformed structural tube (hollow material) EN10025 - Hot-rolled structural steel product EN10297 - seamless steel pipe ASTM A519 for mechanical and general engineering purposes - seamless carbon steel and alloy steel mechanical tube GB/ T1591 - Low alloy high-strength structural steel GB/T8162 - structural seamless steel pipe