Steel A500 GR B Square Tube 4" x 4" x 1/2" 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 Square Tube|A hollow structural section (HSS) used for frames, supports, roll cages, and fabricated assemblies. It's mostly a cut-and-weld product, not typically used as machining stock.