Pipe18STD 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.

Pipe18STD has a 18 in. outside diameter and a 3/8 in. nominal wall.

Also known as NPS 18 pipe (18 in. nominal), standard weight (STD) wall.

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

For strong-axis bending its section modulus is Sx = 84 in³ and its moment of inertia Ix = 756 in⁴, with a plastic modulus Zx = 109 in³.

Detailing dimensions

Outside diameter18"
Nominal wall (t)3/8"

Section properties

Weight70.7 lb/ft
Area (A)19.4 in²
Ix756 in⁴
Sx84 in³
Zx109 in³
rx6.24 in
Iy756 in⁴
Sy84 in³
Zy109 in³
ry6.24 in
J1510 in⁴

Other Pipe18 sizes

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

Pipe18XS

Similar weight pipe sizes

Comparable 70.7 lb/ft sections in other pipe sizes.

Pipe14XS72.2 lb/ft · Sx 62.9 in³Pipe8XXS72.5 lb/ft · Sx 35.8 in³Pipe12XS65.5 lb/ft · Sx 53.2 in³Pipe20STD78.7 lb/ft · Sx 104 in³Pipe16STD62.6 lb/ft · Sx 65.9 in³Pipe16XS82.9 lb/ft · Sx 83.1 in³Pipe10XS54.8 lb/ft · Sx 37 in³Pipe14STD54.6 lb/ft · Sx 50 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 Pipe18STD cut, formed, or fabricated? Huntington Steel & Supply Co.

Browse more: Pipe · Steel Beam Size Chart

Interactive drawing