US structural steel shapes, how their names work, and which shape suits which load.
A steel shape's name tells you its family and size. W12×50 is a wide-flange beam about 12 in deep that weighs 50 lb per foot. This chart explains each family used in US practice, gives dimensions for common W shapes, lists the usual ASTM steel, and shows which shape suits bending, torsion or compression. The European families are in a separate chart.
Designations follow AISC. European sections follow EN 10365.
| Shape | Designation Example | Description | Key Properties | Typical Applications |
|---|---|---|---|---|
| W-Shape (Wide Flange) | W12×50 | I-section with near-parallel flanges | High I, efficient in bending | Beams, columns, primary framing |
| S-Shape (American Standard Beam) | S12×35 | I-section with sloped inner flange | Narrower flange than W | Bridge stringers, older building frames |
| M-Shape (Miscellaneous) | M8×6.5 | Light I-section outside the W series | Light, small sections | Secondary framing |
| HP-Shape (H-Pile) | HP14×73 | Wide flange with equal flange and web thickness | High compressive and driving strength | Foundation piles, columns |
| C-Shape (American Standard Channel) | C10×30 | Channel with sloped inner flange face | Weak in torsion, with the shear centre outside the web | Purlins, girts, bracing members |
| MC-Shape (Miscellaneous Channel) | MC12×50 | Channel outside AISC C series | Wider flanges than C | Framing channels, machine frames |
| L-Shape (Equal Angle) | L4×4×1/2 | Two equal legs at 90° | Low profile, versatile | Bracing, lintels |
| L-Shape (Unequal Angle) | L6×4×1/2 | Two unequal legs at 90° | Asymmetric section properties | Beam clips, shelf angles |
| HSS Round | HSS6.000×0.500 | Hollow circular section | Torsion-efficient | Columns, truss chords |
| Pipe | Pipe 6 Std | Round section to ASTM A53 | Weaker than HSS | Columns, handrails |
| HSS Square | HSS6×6×1/2 | Hollow square section | Equal bending both axes | Columns, moment frames, truss members |
| HSS Rectangular | HSS8×4×1/2 | Hollow rectangular section | Strong axis bending efficient | Beams, truss chords |
| WT-Shape (Structural Tee) | WT6×25 | Cut from W-shape | Half of a W section | Chord members, hangers, connections |
| ST-Shape | ST6×25 | Cut from S12×50 | Half of an S section | Light trusses, secondary members |
| Plate (PL) | PL1/2×12 | Flat plate, various thicknesses | Connection plates, gussets | Gusset plates, base plates, cover plates |
| Bar (Round/Square) | Bar 1" round | Solid round or square bar | Simple tension/compression | Bracing rods, tie rods |
16 rows
Dimensions in inches, area in in². Check final values against the AISC Shapes Database.
| Shape | Depth | Flange width | Web t | Flange t | Area |
|---|---|---|---|---|---|
| W8×31 | 8.00 | 8.00 | 0.285 | 0.435 | 9.1 |
| W14×30 | 13.84 | 6.73 | 0.270 | 0.385 | 8.85 |
| W16×26 | 15.69 | 5.50 | 0.250 | 0.345 | 7.68 |
| W18×35 | 17.70 | 6.00 | 0.300 | 0.425 | 10.3 |
| W21×44 | 20.70 | 6.50 | 0.350 | 0.450 | 13.0 |
| W24×55 | 23.60 | 7.01 | 0.395 | 0.505 | 16.2 |
6 rows
Round HSS and pipe can share dimensions, but they are not the same product. Check which one the design uses.
| Shape | Usual ASTM steel | Fy (ksi) | Fu (ksi) |
|---|---|---|---|
| W, WT | A992 | 50 | 65 |
| Channels, angles | A36 | 36 | 58 |
| HSS, square, rectangular, round | A500 Grade C | 50 | 62 |
| Pipe | A53 Grade B | 35 | 60 |
4 rows
| Name | Means |
|---|---|
| W12×50 | Wide flange, about 12 in deep, 50 lb/ft |
| C10×30 | Channel, 10 in deep, 30 lb/ft |
| L4×4×1/2 | Angle, 4 in legs, 1/2 in thick |
| HSS6×6×1/2 | Square tube, 6 in outside, 1/2 in nominal wall |
| HSS6.000×0.500 | Round tube, 6 in outside, 0.5 in nominal wall |
| WT6×25 | Tee cut from a W shape, 6 in deep, 25 lb/ft |
Depth in a W name is nominal, and the rolled section may differ a little. The last number is weight, so 50 lb/ft is 74.4 kg/m. For European IPE and HEA sections, see the steel beam size chart.
Compare two beams from the table. W16×26 weighs less than W8×31 but has about 40% more section modulus. Steel placed far from the centre does the most work in bending, so depth helps a beam more than weight does.
But deep, narrow sections are less stable. A narrow flange buckles sideways unless it is braced. W8×31 has an 8 in flange, so it does better as a column. To see how a beam deflects, use the beam deflection calculator. The beam load reaction calculator gives the moment to compare.
A channel twists under a load through its web, because its shear centre sits outside the section. Use it where the load passes through that point, or brace it. Angles also carry eccentric loads, because bolts sit off the centre of the section.
This chart helps you choose a shape. It does not size a member, which depends on the span, the loads, the bracing and the code.
By O.E. — Partner, chairman of the board and CEO of a metal products manufacturer for 21 years; the company exports to 45 countries.
Drafted with AI assistance; calculations checked against primary sources and tested with the site's own code. About FlowUtil
Last reviewed
Classification: Standard section-shape designations, with published dimensions
Sources
Steel Construction Manual and Shapes Database, as reported by Engineering ToolBox and EngineerExcel
American Institute of Steel Construction
Are You Properly Specifying Materials?, Modern Steel Construction
American Institute of Steel Construction
W shape rows appear only where two published copies agree. The AISC database itself was not opened, so section properties are not listed here.
The designation gives the family, the nominal depth and the weight per foot. Steels are AISC's usual material for each shape.
Classification: Stable (mature standard)
These values change rarely. Confirm the current edition of the standard for procurement and design.
US designations use depth in inches and weight in pounds per foot.
Go deeper with FlowUtil guides that explain the concepts behind this reference table.
Browse Knowledge Library