HSS18×18×3/4 square/rectangular HSS tube

Detailing dimensions and section properties from the AISC Shapes Database, 16th Edition. Values are shown to the nearest 1/16 in. as they appear on a shop drawing.

HSS18×18×3/4 is a square tube 18 in. by 18 in. with a 3/4 in. nominal wall.

At 171.16 lb per foot it is one of the 8 HSS18×18 sizes, which run from 59.85 to 222.63 lb/ft.

For strong-axis bending its section modulus is Sx = 258 in³ and its moment of inertia Ix = 2320 in⁴, with a plastic modulus Zx = 302 in³.

Detailing dimensions

Depth (Ht)18"
Width (B)18"
Nominal wall (t)3/4"

Section properties

Weight171.16 lb/ft
Area (A)47.1 in²
Ix2320 in⁴
Sx258 in³
Zx302 in³
rx7.02 in
Iy2320 in⁴
Sy258 in³
Zy302 in³
ry7.02 in
J3690 in⁴

Other HSS18×18 sizes

Same nominal size, different weight — useful when you are checking a substitution or a lighter section.

HSS18×18×1/4HSS18×18×5/16HSS18×18×3/8HSS18×18×1/2HSS18×18×5/8HSS18×18×7/8HSS18×18×1

All HSS18×18 sizes and dimensions →

Similar weight HSS shapes

Comparable 171.16 lb/ft sections in other HSS tube sizes.

HSS24×12×3/4171.16 lb/ft · Sx 287 in³HSS22×14×3/4171.16 lb/ft · Sx 281 in³HSS20×16×3/4171.16 lb/ft · Sx 271 in³HSS22.000×0.750170.37 lb/ft · Sx 241 in³HSS24×18×5/8169.91 lb/ft · Sx 325 in³HSS22×20×5/8169.91 lb/ft · Sx 313 in³HSS26.000×0.625169.54 lb/ft · Sx 289 in³HSS20×12×7/8173.43 lb/ft · Sx 248 in³

Detailing values are rounded to the nearest 1/16 in. per the AISC Steel Construction Manual. Verify critical dimensions against the current Manual before fabrication. Need HSS18×18×3/4 cut, formed, or fabricated? Huntington Steel & Supply Co.

Browse more: HSS tube · Steel Beam Size Chart

Interactive drawing