ASTM A213 T91 is the part of ASTM A213 Standard Specification for Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, Heat-Exchanger Tubes.
Structural Tubing is for high stress structural application like bridges, buildings, roll cages, and underwater platforms with wall thickness from 3/16" and up. It is often referred to as Hollow Structural Sections or just the acronym HSS. Production Range OD: 42mm-760mm WT: 4mm-120mm Standard and Steel Grade GB/T 8162 GB/T 17396 or technical agreement. Usage OD(mm) WT(mm) Steel Grade Standard/ Specification Aplication Fields Structural Pipe 42-760 4-120 20#,35#,45#,Q345A/B/C/D,Q390, Q420,25Mn,27SiMn etc. GB/T 8162 General structural and mechanical pipe Vehicle Pipe 45-245 4-35 20Mn2,SAE1527,MZ410R, MZ530R,30Mn2,40Cr,45Mn2 etc. Technical agreement, YB/T5035 Pipe used for automobile axle and automobile semi-shaft Mold Pipe &Tube DN200-DN1200 21CrMo10,21CrMo10-2 etc. Q/OHAD030, technical agreement Centrifugal graphite casting-iron pipe mold Military Pipe 42-760 4-120 30Cr,40Cr,35CrNi1MoA etc. National military standard, agreement Pipe for military use Geology Drilling Pipe &