Equal-Leg Steel Angle Size Chart

Unequal-Leg Steel Angle Size Chart

Weight, area, and moment of inertia values were cross-checked across multiple independent AISC-data-citing engineering references for consistency before inclusion. Radius of gyration (r) was calculated directly from the verified I and A values using r = √(I ÷ A). Values represent standard hot-rolled ASTM A36 angle geometry; sizes not listed here should be verified directly against the current AISC Shapes Database v16.0.

Equal-Leg Angle

A = B. Both legs share the same nominal length, such as L4x4x1/4.

Unequal-Leg Angle

A ≠ B. The legs have different nominal lengths, such as L4x3x1/4, creating an asymmetric cross-section.

Neither type is universally stronger; suitability depends on the specific loading and connection requirements of the project.

For metric designations, L178×102×19.0 means the corresponding dimensions in millimeters.

Equal-Leg Example

L4x4x1/4: both legs 4 in., thickness 1/4 in., weight 6.6 lb/ft.

Unequal-Leg Example

L4x3x1/4: long leg 4 in., short leg 3 in., thickness 1/4 in., weight 5.8 lb/ft.

Why the Larger Leg Is Listed First

This follows AISC’s official EDI naming convention and helps standardize shape identification across databases, drawings, and specifications.

Leg Length

Measured along the nominal outside dimension of each leg.

Thickness

The nominal rolled section thickness, generally consistent across both legs.

Heel and Toe

The heel is the outside corner where the two legs meet; the toe is the free outer edge of each leg. Both terms matter for connection and detailing discussions later on this page.

Small Equal-Leg Angles

Medium Equal-Leg Angles

Large Equal-Leg Angles

Larger equal-leg sizes beyond L8x8 exist in the AISC Shapes Database; do not assume availability from the nominal dimensional series alone. Verify against the current AISC Shapes Database v16.0 for the confirmed size inventory and any size not listed above.

Small Unequal-Leg Angles

Medium Unequal-Leg Angles

Large Unequal-Leg Angles

Leg pairings and thickness ranges beyond those shown should be confirmed from current AISC data before final specification.

Not every thickness is available for every leg combination. ASTM A6/A6M governs general dimensional tolerances and shape requirements for rolled structural steel shapes, including angles.

ASTM’s inch-pound and SI tables may be independently rationalized rather than exact converted specification values; ASTM A6/A6M explicitly notes this for its SI annex.

kg/m values calculated as lb/ft × 1.48816 (exact conversion factor). Weight depends on section dimensions, thickness, and actual published area; for sizes not shown, see the steel weight calculator or metal weight calculator.

The full AISC reference tables above remain the preferred method over hand calculation.

I_x and I_y describe resistance to bending about the geometric x and y axes. For equal-leg angles, I_x = I_y (for example, L4x4x3/8 has Ix = Iy = 4.36 in⁴). For unequal-leg angles, I_x ≠ I_y (for example, L4x3x3/8 has Ix = 3.96 in⁴ but Iy = 1.92 in⁴), and the geometric axes may not align with the actual principal axes of bending. The AISC Specification contains special single-angle flexural provisions that reflect this asymmetric behavior.

Section modulus relates cross-sectional geometry to bending stress capacity. This page keeps detailed flexural capacity calculations outside its scope; see the Beam Deflection Chart for related bending concepts.

Steel angles have geometric x/y axes as well as rotated principal axes (often called major/minor or w/z axes) that govern actual bending behavior. The centroid is not located at the leg intersection (the heel), which further complicates simple geometric assumptions.

Equal-Leg Angle

Has more geometric symmetry than an unequal-leg angle, with principal axes oriented at 45 degrees to the legs.

Unequal-Leg Angle

Principal axes rotate relative to the geometric legs at an angle that depends on the specific leg ratio, making orientation-sensitive design essential.

This matters because bolts or welds may connect through only one leg, so the applied force does not pass through the centroid. That eccentricity can generate additional bending or torsional effects, which is one reason single-angle tension or compression members are not always as straightforward as a simple area calculation would suggest.

The inside root or fillet radius and the toe radius affect detailing, bolt clearance, weld access, and actual section area and properties. Do not approximate exact radii unless sourced from AISC database values for the specific angle size.

The gage line is the standard distance from the heel to the bolt line on a given leg. Workable gage refers to the practical, commonly used bolt-line location that balances edge distance requirements with available leg width. Bolt holes cannot simply be placed anywhere on the leg; minimum edge distance and gage requirements interact with leg length and thickness. AISC’s shape database and manual resources explicitly include workable-gage dimensions among published shape data, which is a strong reason to use AISC as the primary reference source rather than a generic table.

AISC’s EDI naming convention uses a “2L” prefix for double angles, and may additionally specify back-to-back spacing along with long-leg-back-to-back (LLBB) or short-leg-back-to-back (SLBB) orientation. This page is mainly focused on single-angle sizing, so double-angle coverage is kept concise.

Orientation affects overall geometry and connection layout for double-angle members. This page does not expand into full double-angle design guidance.

ASTM A36

ASTM A36 has traditionally been the preferred material specification for angles, with a minimum yield strength of 36 ksi and minimum tensile strength of 58 ksi.

50 ksi Angle Materials

Angles, channels, and plates are now commonly available in 50 ksi material as well, such as ASTM A572 Grade 50 or ASTM A529 Grade 50. AISC guidance notes that A36 remains common, but 50 ksi angle material has become increasingly available, and availability in any specific grade should be confirmed prior to specification.

ASTM A6/A6M provides general requirements and permitted dimensional and mass variations for rolled structural steel shapes, including leg-length tolerances, thickness tolerances, squareness, mass or weight variation, and straightness where applicable. Full tolerance tables are not reproduced here; consult the current standard directly for project-specific tolerance requirements.

Not all structural angles are ASTM A36. The applicable steel specification must come from the project documents and material ordering requirements, and higher-strength alternatives such as ASTM A572 or A529 may be specified depending on the application.

AISC’s current Shapes Database v16.0 corresponds to the 16th Edition Steel Construction Manual, includes current dimensions and properties, provides both U.S. customary and metric units, and follows standardized EDI shape naming. The tables on this page use cross-verified values consistent with this database as the primary dimensional and section-property dataset.

A published standard shape may exist as a regularly stocked size, a mill-order shape, or something with limited regional availability. Material grade and thickness availability can also vary. AISC itself notes in its design-guide materials that availability can evolve and should be checked. Do not present every AISC-listed shape as guaranteed local stock.

Angles may be supplied in standard mill or service-center lengths and cut to project dimensions. Actual stock lengths depend on supplier, angle size, grade, and region. This page does not state one universal standard angle length.

Bracing

Angles are frequently used as diagonal braces in frames.

Trusses

Single and double angles are common truss chord and web members.

Lintels and Edge Supports

Angles support masonry or other loads over openings.

Connection Angles

Angles frequently serve as clip angles and connection elements between other members.

Shelf and Seat Angles

Used to support masonry veneer or beam reactions at bearing points.

Do not treat any specific size, such as L4x4x1/4, as automatically appropriate for a lintel or any other application without structural design.

See the Structural Steel Shapes Chart, HSS Size Chart, and Steel Beam Size Chart for shape-specific reference.

Selection depends on tension, compression, bending, shear, unbraced or effective length, slenderness, connection eccentricity, bolt or weld layout, load direction, material grade, and corrosion or fire requirements.

Single angles can experience unsymmetrical bending and flexural-torsional effects, and connection eccentricity plays a larger role than in doubly symmetric shapes. Long-leg versus short-leg orientation changes principal-axis behavior significantly. AISC has specific single-angle flexural provisions, and the specification even distinguishes unequal-leg cases depending on whether the long leg or short leg is in compression.