HSS6-5/8x3/8 (HSS6.625x.375) – HSS Shapes - Round

HSS6-5/8x3/8 is a 6.625 in (168 mm) diameter round hollow section with a 3/8 in (10 mm) nominal wall, weighing 25.06 lb/ft (37.3 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.