150×18 UB | 150UB18 | Universal Beams | Section Properties | Australia NZ | Metric, SI, Imperial & US Units

The steel section 150×18 UB falls under the section category of Universal Beams. The section 150×18 UB is denoted by the Standard Industry section notation – 150UB18. In Australia and New Zealand, the nominal section dimensions and weights of hot-rolled sections are defined in Appendix D of AS/NZS 3679.1:2016 Structural Steel – Hot-Rolled Bars and Sections. These dimensions are used to calculate the design section properties of this section.

150UB18 | Universal Beams
150UB18 | Universal Beams

Summary of Geometrical and Sectional Properties of 150UB18 or 150×18 UB

Section properties of 150UB18 in metric units and imperial units (US Customary Units) are summarised in the table below

Property ComponentMetric UnitsImperial Units (US Units)
Depth of section, d15.50 cm 6.10 in 
Breadth of section or Flange width, b7.50 cm 2.95 in  
Flange thickness, tf0.95 cm 0.37 in 
Web thickness, tw0.60 cm 0.24 in 
Root radius, r0.80 cm 0.31 in 
Total Area of section, A22.96 cm2 3.56 in2 
Second moment of area about x-axis, Ixx905.10 cm4 21.75 in4 
Second moment of area about y-axis, Iyy67.18 cm4 1.61 in4 
Radius of gyration about x-axis, rx6.28 cm 2.47 in 
Radius of gyration about y-axis, ry1.71 cm 0.67 in 
Elastic section modulus about x-axis, Zxx116.80 cm3 7.13 in3 
Elastic section modulus about y-axis, Zyy17.91 cm3 1.09 in3 
Plastic section modulus about x-axis, Sxx135.10 cm3 8.24 in3 
Plastic section modulus about y-axis, Syy28.21 cm3 1.72 in3 
Warping Constant, Iw3556.00 cm6 13.24 in6 
Torsional Constant, J6.05 cm4 0.15 in4 
Mass of section, M18.02 kg/m 12.11 lb/ft 
Summary of Geometrical and Sectional Properties of 150×18 UB

Summary of Geometrical and Sectional Properties of 150×18 UB in millimetres, mm

Section properties of 150UB18 in millimeters, mm are summarised in the table below

Property ComponentMetric Units
Depth of section, d155.00 mm 
Breadth of section or Flange width, b75.00 mm 
Flange thickness, tf9.50 mm 
Web thickness, tw6.00 mm 
Root radius, r8.00 mm 
Total Area of section, A2296.00 mm2 
Second moment of area about x-axis, Ixx9051000.00 mm4 
Second moment of area about y-axis, Iyy671800.00 mm4 
Radius of gyration about x-axis, rx6.28 cm 
Radius of gyration about y-axis, ry17.11 mm 
Elastic section modulus about x-axis, Zxx116800.00 mm3 
Elastic section modulus about y-axis, Zyy17910.00 mm3 
Plastic section modulus about x-axis, Sxx135100.00 mm3 
Plastic section modulus about y-axis, Syy28210.00 mm3 
Warping Constant, Iw3556000000.00 mm6 
Torsional Constant, J60470.00 mm4 
Mass of section, M18.02 gm/mm 
Summary of Geometrical and Sectional Properties of 150×18 UB in millimetres, mm

Geometry of 150×18 UB in mm – SI units

Total depth of section = Section depth, d = 155.00 mm

Total breadth of section = Section width, b = 75.00 mm

Flange thickness, tf = 9.50 mm

Web thickness, tw = 6.00 mm

Root radius, r = 8.00 mm

Total Area of section, A = 2296.00 mm2 

Mass of section, M = 18.02 kg/m 

Sectional Properties of 150×18 UB in mm – Metric units

The Second Moment of Area or Second Area Moment or Quadratic Moment of Area or Area Moment of Inertia or moment of Inertia about x-axis, Ixx = 9051000.00 mm4

The Second Moment of Area or Second Area Moment or Quadratic Moment of Area or Area Moment of Inertia or moment of Inertia about y-axis, Iyy = 671800.00 mm4

Radius of gyration about x-axis, rx = 62.79 mm

Radius of gyration about y-axis, ry = 17.11 mm

Elastic section modulus about x-axis, Zxx = 116800.00 mm3

Elastic section modulus about y-axis, Zyy = 17910.00 mm3

Plastic section modulus about x-axis, Sxx = 135100.00 mm3

Plastic section modulus about y-axis, Syy = 28210.00 mm3

Warping Constant, Iw = 3556000000.00 mm6

Torsional Constant, J = 60470.00 mm4

Structural Design Parameters of 150×18 UB or 150UB18 in mm – Metric units

Based on the design application and structure type, Universal Beams are to be designed in accordance with AS-NZS 5100.6-2017 and AS 4100:2020. Another design guide available for designers is AISC – Design of Structural Connection 4th Edition 1994 published by Australian Steel Institute.

Depth of web between flanges, dw = 136.00 mm 

Surface area = 0.58 m2/m  

Ratio of outstanding flange/thickness of flange =  3.947

Web slenderness ratio or ratio of clear web depth/thickness of web =  22.670

Buckling Parameter of section =  0.882

Trivia – Hot-rolled Universal Beam Structural Steel Sections

Grade 300 Steel is the most common and standard grade manufactured by most manufacturers in Australia for hot rolled Structural Steel Sections. Depending on project and client demands, other grades available in the market are 300L0, 300L15, 350, 350L0 & 350L15.

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Common stock lengths available in the market are 9.0m, 10.5m, 12.0m, 13.5m, 15.0m, 16.5m, 18.0m & 20.0. However, some lengths may not be available depending on the supplier. 

Hot-rolled Structural Steel Sections are usually supplied in Mill Finish. Although, other finishes are available on demand or special orders.

FAQs on 150×18 UB or 150UB18

How much does it cost to cut 150 UB 18 beam?

An indicative cost of cutting 150UB14 beam in Australia is $7/cut. However, the final rates will depend largely on volume of order and tools used.

What is the cost of 150UB18 per linear metre?

In Australia, the retail selling rate of 150UB18 is $82 per linear metre for raw/mill finish and $91 per linear metre for primed finish, excluding GST and volume discounts.

What is the cost of drilling holes 150 UB 18 beam?

Suppliers can charge up to $3 per hole for drilling holes in hot rolled beams in Australia.

What is the weight of 150UB18 per meter?

The weight of 150UB18 per meter is 18.02 kg/m

What is the cross-sectional area of 150UB18?

The cross-sectional area of 150UB18 is 2296.00 mm2 

What is the exposed surface area of 150UB18 per meter?

The exposed surface area of 150UB18 per meter is 0.58 m2/m 

Universal Beams are available in section depths of 150mm, 180mm, 200mm, 250mm, 310mm, 360mm, 410mm, 460mm, 530mm & 610mm.Data on this page has been verified and validated with multiple data sources and reviewed regularly for correctness and accuracy, if you have any comments or suggestions, please reach out to us here.