A hollow structural section ( HSS ) is a type of metal profile with a
hollow cross section. The term is used predominantly in the United States, or
other countries which follow US construction or engineering terminology.
HSS members can be circular, square, or rectangular sections, although other
shapes such as elliptical are also available. HSS is only composed of
structural steel per code.
HSS is sometimes mistakenly referenced as hollow structural steel.
Rectangular and square HSS are also commonly called tube steel or box
section. Circular HSS are sometimes mistakenly called steel pipe , although
true steel pipe is actually dimensioned and classed differently from HSS.