An equal angle has two legs of the same length, such as L102x102x7.9, and an unequal angle has one long and one short leg, such as L152x102x7.9. At the same weight, an unequal angle set with its long leg vertical is noticeably stiffer as a beam or lintel, while an equal angle is the better all-rounder for bracing, frames and struts. Unequal angles are written long leg first, and on drawings the orientation (long leg vertical or horizontal) matters as much as the size.
How angle sizes are written
Canadian drawings name angles by their legs and thickness in millimetres:
- Equal leg: L102x102x7.9 means two 102 mm legs, 7.9 mm thick. Imperial: L4x4x5/16.
- Unequal leg: L152x102x7.9 means a 152 mm leg and a 102 mm leg, 7.9 mm thick. Imperial: L6x4x5/16.
The standard convention lists the long leg first. Lintel tables and some drawings list the vertical leg first instead, so an L102x89 lintel is set with the 102 mm leg upright. When in doubt, look for the notes LLV (long leg vertical) or LLH (long leg horizontal), or ask.
For the full list of rolled sizes and weights, see our steel angle size chart. It covers equal angles from L51x51 to L305x305 and unequal angles from L64x38 to L203x152.
A quick check on weight: mass in kg/m is close to (leg 1 + leg 2 minus thickness) x thickness x 0.00785, with all dimensions in millimetres. For L152x102x7.9 that is (152 + 102 minus 7.9) x 7.9 x 0.00785, or about 15.3 kg/m. Our angle weight per metre guide has the full table.
Same weight, side by side
The comparison that matters is equal versus unequal at the same mass, because steel is bought by weight. Properties are converted from the AISC Shapes Database and rounded.
About 12.2 kg/m
| Angle | Orientation | I (10⁶ mm⁴) | S (10³ mm³) | Minimum r (mm) |
|---|---|---|---|---|
| L102x102x7.9 | Either leg vertical | 1.53 | 20.8 | 19.8 |
| L127x76x7.9 | Long leg vertical | 2.60 | 30.6 | 16.5 |
| L127x76x7.9 | Long leg horizontal | 0.72 | 12.1 | 16.5 |
About 15.3 kg/m
| Angle | Orientation | I (10⁶ mm⁴) | Minimum r (mm) |
|---|---|---|---|
| L127x127x7.9 | Either leg vertical | 3.10 | 25.1 |
| L152x102x7.9 | Long leg vertical | 4.75 | 22.2 |
| L152x102x7.9 | Long leg horizontal | 1.72 | 22.2 |
Three things to take from these tables:
- Long leg vertical is the strong way. At the same weight, the unequal angle set LLV is about 50% to 70% stiffer than the equal angle. That is why lintels and ledger angles are usually unequal, long leg up.
- Long leg horizontal is the weak way. The same unequal angle laid flat has only a quarter to a third of its LLV stiffness, less than the equal angle. Installing an unequal angle the wrong way round throws away most of its strength.
- Equal angles win in compression. Their minimum radius of gyration is larger, so for a brace or strut of the same weight an equal angle resists buckling better.
These are section properties for comparison, not capacities. A real lintel or brace is sized for its loads, span and connections; see steel angle load capacity for how that works.
When an unequal angle is the better choice
- Masonry lintels. The horizontal leg carries the brick or stone, so its length is set by the masonry it supports. The vertical leg provides the stiffness for the span. In the 2024 Ontario Building Code table for angle lintels supporting masonry veneer (Table 9.20.5.2.-B), the sizes for longer spans are unequal angles such as 127 x 89 and 152 x 89, listed vertical leg first, with an 89 mm or 102 mm horizontal leg. See steel lintel sizes under the Ontario Building Code.
- Shelf and ledger angles. A short horizontal leg for the bearing and a longer vertical leg for bolts or stiffness.
- Connections with uneven needs. Clip and seat angles where one leg needs room for two rows of bolts and the other only one.
- Fitting tight spaces. Where one leg has to stay narrow to clear a finish, cladding or another member.
When an equal angle is the better choice
- Bracing and struts. Cross bracing, knee braces and light truss members, where buckling resistance matters most.
- Frames and corners. Equipment frames, door and hatch frames, curb angles and edge protection, where both faces show or connect.
- Unknown or mixed loading. An equal angle has the same properties about both leg axes, so it is more forgiving if the load direction varies.
- Availability. Equal angles are the most widely stocked. Some unequal sizes and thicknesses take longer to source, so ask before you design around an uncommon one.
Practical points for unequal angles
Mark the orientation. On shop drawings and on the piece itself, the orientation should be clear. A lintel installed LLH instead of LLV can sag and crack the masonry above.
Gauge lines differ by leg. Bolt holes in each leg sit on a standard gauge line measured from the heel, and a longer leg can take a different gauge or two rows of bolts. See steel angle heel, toe and gauge for how fabricators lay these out.
Angles bend sideways under vertical load. Because an angle's principal axes are tilted, a load applied straight down on an unrestrained angle makes it deflect partly sideways. Lintels are held by the masonry; loose angles used as beams need bracing or a designer's check.
Substitutions. Swapping an unequal angle for an equal one (or the reverse) changes the properties, the bearing and the connections. Treat it as a substitution that needs the designer's approval. If a specified size is hard to get, an alternative angle or a bent plate may work, but only once the designer agrees.
What to include when ordering angle
- The size exactly as drawn, legs and thickness, in metric or imperial. For unequal angles, keep the leg order as shown.
- The orientation (LLV or LLH) for each piece, so it can be marked.
- The grade, from the drawings or specification. Angles are commonly supplied to CSA G40.21 grades or dual-certified to an ASTM grade.
- Cut lengths and quantities, including bearing length at each end for lintels.
- Holes, slots, mitres and welded parts, or the shop drawings.
- The finish: bare, primed, painted or galvanized. Lintels in masonry must be protected from corrosion under the building code, and exterior angles often call for galvanizing.
Angles cut and fabricated to order
We supply equal and unequal angles cut to length and fabricated to drawings, with punched or drilled holes, slots, mitres, welded clips and lintel assemblies, in our CWB certified shop. We can prime or galvanize to suit and deliver across the GTA and Ontario. Send the size, orientation and quantities, or your drawings, and we'll confirm what we can supply.
Send your drawings for a quote, or browse our steel products, including lintels, plates, channels and posts.
Frequently asked questions
What is equal angle steel?
Equal angle is a hot-rolled steel angle with both legs the same length, such as L102x102x7.9 (4 x 4 x 5/16 in). It has the same properties about both leg axes, so orientation matters less, and it is the most widely stocked type of angle.
How are unequal angle sizes written?
Long leg first, then short leg, then thickness. L152x102x9.5 has a 152 mm leg, a 102 mm leg and 9.5 mm thickness, the same section as an imperial L6x4x3/8. On lintel drawings and tables, sizes are often written as vertical leg by horizontal leg.
Is unequal angle stronger than equal angle?
Used with the long leg vertical as a beam or lintel, an unequal angle is stiffer than an equal angle of the same weight. As a brace or strut in compression, an equal angle usually does better because its weakest-axis radius of gyration is larger.
What does LLV mean on a steel drawing?
LLV means long leg vertical, and LLH means long leg horizontal. They tell the fabricator and installer how an unequal angle is to be oriented, which matters because the angle's stiffness changes a lot between the two.
