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Structural · W — wide-flange

W18x55 Steel Beam — Dimensions & Properties

W18x55 weighs 55 lb/ft and is about 18.11 in deep. Below: the full AISC section properties, a scaled cross-section, and a pre-filled weight calculator.

Weight
55lb/ft
Depth
18.11in
Width
7.53in
Area
16.2in²
Shape
W18X55 · W — wide-flange

Enter feet + inches, e.g. 20' or 18' 6".

= 20' (240″)
pcs
Cost estimate (optional)
$/lb

Optional. Prices are volatile — use your current mill/supplier rate.

Total weight
1 × W18X55
1,100lb
Per piece
1100lb
Pieces
1
Total
1100lb
Tons
0.55t
d18.11"bf 7.53"tw 0.39
ƒShow the math
  1. 1.Weight per foot (from AISC)per AISC Shapes Database v16.0

    W18X55 is a listed shape; its nominal weight is a published property.

    = 55 lb/ft
  2. 2.Length in feet
    length (in) ÷ 12
    240 ÷ 12
    = 20 ft
  3. 3.Weight per piece
    weight per foot × length
    55 × 20
    = 1100 lb
  4. 4.Total weight
    weight per piece × quantity
    1100 × 1
    = 1100 lb
  5. 5.Convert to tons
    total lb ÷ 2000
    1100 ÷ 2000
    = 0.55 tons

Section properties

Geometry
Weight
55lb/ft
Area, A
16.2in²
Depth, d
18.11in
Flange width, bf
7.53in
Flange thick, tf
0.63in
Web thick, tw
0.39in
Strong axis (x-x)
Ix
890in⁴
Sx
98.3in³
Zx
112in³
rx
7.41in
Weak axis (y-y)
Iy
44.9in⁴
Sy
11.9in³
Zy
18.5in³
ry
1.67in
Torsion & warping
J
1.66in⁴
Cw
3,430in⁶
Before you rely on this
  • Listed weight is the AISC theoretical (nominal) weight per foot. Actual mill weight varies within ASTM rolling tolerance, roughly ±2.5%.
  • This is bare member steel only. Add plates, stiffeners, connections, bolts, and coatings for a full erected-steel takeoff.

Similar shapes

Same series and nearest depths — compare weight and section modulus when you are sizing.

W18x35 35 lb/ftW18x40 40 lb/ftW18x46 46 lb/ftW18x50 50 lb/ftW18x65 65 lb/ftW18x76 76 lb/ftW18x86 86 lb/ftW18x97 97 lb/ftW16x100 100 lb/ftW16x89 89 lb/ft

W18x55 — questions

How much does a W18x55 weigh per foot?
A W18x55 weighs 55 lb/ft. Over a 20-foot length that is 1,100 lb (0.55 tons); a 30-foot length is 1,650 lb.
What are the dimensions of a W18x55?
W18x55 has an actual depth of 18.11 in and a flange width of 7.53 in, a flange thickness of 0.63 in, and a web thickness of 0.39 in. Cross-sectional area is 16.2 in².
What is the moment of inertia and section modulus of a W18x55?
About its strong axis, W18x55 has a moment of inertia Ix of 890 in⁴ and a section modulus Sx of 98.3 in³, with a plastic section modulus Zx of 112 in³. Use these with your engineer's design values — they are geometric properties, not an allowable load.
What does W18x55 mean?
The W means wide-flange. The first number is the nominal depth in inches and the second is the weight in pounds per foot — so W18x55 is a nominally 18-inch-deep wide-flange beam weighing 55 lb/ft (actual depth 18.11 in).

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Sources & references

Estimates for planning purposes only. Verify all results against the code edition adopted in your jurisdiction and with your Authority Having Jurisdiction (AHJ). This tool is not a substitute for a licensed professional engineer. See our methodology, sources, and code editions.

Data: AISC Shapes Database v16.0, © AISC — used per its developer-use provision.