HSS18×8×3/8 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.

HSS18×8×3/8 is a rectangular tube 18 in. by 8 in. with a 3/8 in. nominal wall.

At 63.21 lb per foot it is one of the 5 HSS18×8 sizes, which run from 42.84 to 101.85000000000001 lb/ft.

For strong-axis bending its section modulus is Sx = 79 in³ and its moment of inertia Ix = 711 in⁴, with a plastic modulus Zx = 98.7 in³.

Detailing dimensions

Depth (Ht)18"
Width (B)8"
Nominal wall (t)3/8"

Section properties

Weight63.21 lb/ft
Area (A)17.3 in²
Ix711 in⁴
Sx79 in³
Zx98.7 in³
rx6.4 in
Iy202 in⁴
Sy50.5 in³
Zy56.1 in³
ry3.41 in
J510 in⁴

Other HSS18×8 sizes

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

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

All HSS18×8 sizes and dimensions →

Similar weight HSS shapes

Comparable 63.21 lb/ft sections in other HSS tube sizes.

HSS20×6×3/863.21 lb/ft · Sx 79.2 in³HSS16×10×3/863.21 lb/ft · Sx 77 in³HSS14×12×3/863.21 lb/ft · Sx 73.2 in³HSS24×14×1/463.25 lb/ft · Sx 117 in³HSS22×16×1/463.25 lb/ft · Sx 114 in³HSS16.000×0.37562.64 lb/ft · Sx 65.7 in³HSS10.000×0.62562.64 lb/ft · Sx 38.3 in³HSS16×4×1/262.46 lb/ft · Sx 56.9 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 HSS18×8×3/8 cut, formed, or fabricated? Huntington Steel & Supply Co.

Browse more: HSS tube · Steel Beam Size Chart

Interactive drawing