Pipe18XS pipe

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.

Pipe18XS has a 18 in. outside diameter and a 1/2 in. nominal wall.

Also known as NPS 18 pipe (18 in. nominal), extra strong (XS) wall.

At 93.5 lb per foot it is the heaviest of the 2 Pipe18 sizes, which run from 70.7 to 93.5 lb/ft.

For strong-axis bending its section modulus is Sx = 106 in³ and its moment of inertia Ix = 956 in⁴, with a plastic modulus Zx = 139 in³.

Detailing dimensions

Outside diameter18"
Nominal wall (t)1/2"

Section properties

Weight93.5 lb/ft
Area (A)24.8 in²
Ix956 in⁴
Sx106 in³
Zx139 in³
rx6.21 in
Iy956 in⁴
Sy106 in³
Zy139 in³
ry6.21 in
J1910 in⁴

Other Pipe18 sizes

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

Pipe18STD

Similar weight pipe sizes

Comparable 93.5 lb/ft sections in other pipe sizes.

Pipe24STD94.7 lb/ft · Sx 152 in³Pipe26STD103 lb/ft · Sx 178 in³Pipe20XS104 lb/ft · Sx 132 in³Pipe10XXS104 lb/ft · Sx 65.6 in³Pipe16XS82.9 lb/ft · Sx 83.1 in³Pipe20STD78.7 lb/ft · Sx 104 in³Pipe8XXS72.5 lb/ft · Sx 35.8 in³Pipe14XS72.2 lb/ft · Sx 62.9 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 Pipe18XS cut, formed, or fabricated? Huntington Steel & Supply Co.

Browse more: Pipe · Steel Beam Size Chart

Interactive drawing