The Difference between Structural Pipe and Fluid Pipe
SteelTek 3/8-in x 36-in Structural Black Pipe in the Structural Pipe & Fittings department at Lowes.com
Structural Aluminum Pipe - Series 6061-T6
eoere 8 Sets 4 Way Structural Pipe Connector, Metal Clamp Fittings, Fit for 1"(O.D. 25.4 mm) Stainless Steel Pipe (Doesn't fit US 1" Electrical-Metallic Tubing) - Amazon.com