HSS18×18×7/8 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.

HSS18×18×7/8 is a square tube 18 in. by 18 in. with a 7/8 in. nominal wall.

At 197.24 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 = 292 in³ and its moment of inertia Ix = 2630 in⁴, with a plastic modulus Zx = 346 in³.

Detailing dimensions

Depth (Ht)18"
Width (B)18"
Nominal wall (t)7/8"

Section properties

Weight197.24 lb/ft
Area (A)54.3 in²
Ix2630 in⁴
Sx292 in³
Zx346 in³
rx6.96 in
Iy2630 in⁴
Sy292 in³
Zy346 in³
ry6.96 in
J4220 in⁴

Other HSS18×18 sizes

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

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

All HSS18×18 sizes and dimensions →

Similar weight HSS shapes

Comparable 197.24 lb/ft sections in other HSS tube sizes.

HSS24×12×7/8197.24 lb/ft · Sx 326 in³HSS20×12×1195.4 lb/ft · Sx 274 in³HSS16×16×1195.4 lb/ft · Sx 249 in³HSS24×18×3/4201.79 lb/ft · Sx 382 in³HSS22×20×3/4201.79 lb/ft · Sx 367 in³HSS26.000×0.750202.44 lb/ft · Sx 342 in³HSS30×10×3/4191.58 lb/ft · Sx 363 in³HSS24×16×3/4191.58 lb/ft · Sx 350 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 HSS18×18×7/8 cut, formed, or fabricated? Huntington Steel & Supply Co.

Browse more: HSS tube · Steel Beam Size Chart

Interactive drawing