HSS Shapes - Square - HSS18x18x.3125

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.