The W6 series is a family of small American standard wide flange H-beams that share the same nominal depth class but differ in flange width, web and flange thickness, and weight. In steel structures these sections are commonly specified in ASTM A36, A572 Grade 50, or A992. The choice of size depends mainly on the load level and the stiffness required by the design.
W6x12
The W6x12 has a web height of about 153 mm and a flange width of about 102 mm, with approximate cross-section dimensions of 153 by 102 by 5.8 by 7.1 mm and a unit weight of about 18 kg per meter. It is the lightest member of the group and is intended for light-load scenarios such as secondary beams in industrial plants, light brackets, and other weight-sensitive structures where economy of material is the main concern.
W6x15
The W6x15 has a flange width and web height of about 152 mm, with approximate dimensions of 152 by 152 by 5.8 by 6.6 mm and a unit weight of about 22.5 kg per meter. Its more compact and balanced cross-section suits medium-load applications such as small-span main beams or columns, where the design must balance weight against load-carrying capacity.
W6x16
The W6x16 has a web height of about 160 mm and a flange width of about 102 mm, with approximate dimensions of 160 by 102 by 6.6 by 10.3 mm and a unit weight of about 24 kg per meter. The thicker web is the distinguishing feature of this size, and it is used where high local shear loads must be resisted, such as equipment support platforms and short heavily loaded members.
W6x20
The W6x20 has a web height of about 153 mm and a flange width of about 157 mm, with approximate dimensions of 157 by 153 by 6.6 by 9.3 mm and a unit weight of about 29.8 kg per meter. It is the heaviest member of the W6 group and is selected for heavy-load structures such as large-span plant main beams and bridge support members that require high stiffness and bending capacity.
Material Grade Selection
The three common grades cover different strength levels. A36 has a minimum yield strength of about 250 MPa and is economical for lightly loaded members. A572 Grade 50 raises the minimum yield strength to about 345 MPa, allowing smaller sections for the same load. A992 also provides 345 MPa minimum yield strength but with tighter controls on the yield-to-tensile ratio and better weldability, which makes it the preferred grade for wide flange shapes in seismic and modern building frames. The size and grade are selected together by the design engineer.
Frequently Asked Questions
Q: What sizes are in the W6 series?
A: The common sizes are W6x12, W6x15, W6x16, and W6x20, with unit weights from about 18 to 29.8 kg per meter.
Q: What is the difference between W6x12 and W6x20?
A: W6x12 is the lightest and suits secondary light-load members, while W6x20 is the heaviest and suits main beams and members that need high stiffness.
Q: Which steel grade should be used for W6 beams?
A: A36 for general and light duty, A572 Grade 50 for higher strength, and A992 for wide flange shapes where weldability and seismic performance matter.
Q: What does the W in W6x12 mean?
A: W identifies the member as an American standard wide flange shape with parallel flange surfaces.
Q: Are the metric dimensions exact?
A: The metric dimensions are approximate conversions of the imperial standard, and exact values should be taken from the standard section tables.
Q: Where are W6 beams commonly used?
A: In industrial plant secondary framing, small-span beams and columns, equipment support platforms, and light bridge support members.