HSS18×8×5/8 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.

HSS18×8×5/8 is a rectangular tube 18 in. by 8 in. with a 5/8 in. nominal wall.

At 101.85000000000001 lb per foot it is the heaviest 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 = 122 in³ and its moment of inertia Ix = 1100 in⁴, with a plastic modulus Zx = 156 in³.

Detailing dimensions

Depth (Ht)18"
Width (B)8"
Nominal wall (t)5/8"

Section properties

Weight101.85000000000001 lb/ft
Area (A)28 in²
Ix1100 in⁴
Sx122 in³
Zx156 in³
rx6.27 in
Iy306 in⁴
Sy76.6 in³
Zy87.8 in³
ry3.31 in
J797 in⁴

Other HSS18×8 sizes

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

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

All HSS18×8 sizes and dimensions →

Similar weight HSS shapes

Comparable 101.85000000000001 lb/ft sections in other HSS tube sizes.

HSS20×6×5/8101.85000000000001 lb/ft · Sx 122 in³HSS16×10×5/8101.85000000000001 lb/ft · Sx 119 in³HSS14×12×5/8101.85000000000001 lb/ft · Sx 113 in³HSS26.000×0.375102.73 lb/ft · Sx 178 in³HSS16.000×0.625103 lb/ft · Sx 105 in³HSS24×8×1/2103.3 lb/ft · Sx 159 in³HSS22×10×1/2103.3 lb/ft · Sx 158 in³HSS20×12×1/2103.3 lb/ft · Sx 155 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 HSS18×8×5/8 cut, formed, or fabricated? Huntington Steel & Supply Co.

Browse more: HSS tube · Steel Beam Size Chart

Interactive drawing