HSS3-1/2x1/8 (HSS3.5x.125) – HSS Shapes - Round

HSS3-1/2x1/8 is a 3.5 in (89 mm) diameter round hollow section with a 1/8 in (3 mm) nominal wall, weighing 4.51 lb/ft (6.7 kg/m).

Round HSS are closed, circular tube sections, sharing the torsional and biaxial strength advantages of rectangular HSS but in a circular profile that's often preferred where appearance matters — exposed columns, canopy supports, and architectural framing — as well as more utilitarian uses like handrail posts and bollards. The circular shape distributes compressive and torsional loads evenly in every direction, making round HSS a strong, materially efficient choice wherever a round column or post is wanted rather than a square or rectangular one.