Steel A500 GR B Rectangular Tube 4" x 8" x 3/8" wall Price

About A500 GR B|Structural tubing, Grade B. Minimum 42 KSI yield, 58 KSI tensile. This is the lower-strength tier of the A500 spec (Grade C bumps yield to 46 KSI). Most mills today produce to Grade C anyway and dual-certify, so standalone Grade B is becoming less common in new production. If you're seeing it, it's either older inventory or the customer specified B because that's what the engineer's calculation needed. Same welded-seam HSS (hollow structural sections) product as A500 GR B/C. Not for precision machining. Compare to A500 GR B/C (dual-cert, effectively the same product) and A36 (plate/bar equivalent structural grade).

About Rectangular Tube|A hollow structural section used for frames, machine guards, and fabricated assemblies where you need different dimensions on each axis. Same fabrication use case as square tube with more flexibility in cross-section.