HSS3-1/2x3-1/2x5/16 (HSS3.5x3.5x.3125) – HSS Shapes - Square

HSS3-1/2x3-1/2x5/16 is a 3.5 in (89 mm) square hollow section with a 5/16 in (8 mm) nominal wall, weighing 12.7 lb/ft (18.9 kg/m).

Square HSS (Hollow Structural Sections) are closed, tube-shaped sections with equal depth and width. The closed profile gives excellent torsional stiffness and identical strength about both axes, a meaningful advantage over open shapes such as W or C sections. That symmetry makes square HSS a natural choice for columns, particularly where architecturally exposed structural steel is part of the design, and for posts, bracing and light framing where equal biaxial capacity and a clean profile matter more than bending capacity in one direction.