Equal-leg structural angle
Legs of the same length with a root fillet radius. The default for frames, bracing, gussets and cross-members. Dimensions follow the Aluminum Association standard series used in ASTM B308.
Extruded structural section guide
6061 Aluminium Angle: Sizes, Weights and T6 Properties
6061 aluminium angle is an extruded L-section in the Al-Mg-Si-Cu alloy 6061, almost always supplied in the T6 or T6511 temper for a guaranteed minimum yield of 240 MPa (35 ksi). It is the structural angle of choice for frames, bracing, brackets and supports that must be strong, light, weldable and corrosion resistant. This guide covers profiles, size and weight tables, standards, tolerances and how to fabricate and order it.
- Alloy
- 6061 (EN AW-6061, A96061)
- Usual temper
- T6 / T6511
- Min. yield (T6)
- 240 MPa / 35 ksi
- Standards
- ASTM B221 · B308 · EN 755
What is 6061 aluminium angle?
An angle is the simplest structural section: two legs joined at 90°. In 6061 it is produced by hot extrusion through a steel die, quenched at the press or in a furnace, stretched straight and then artificially aged to the T6 condition. The result is a section with roughly the yield strength of mild structural steel at about one third of the weight.
6061 is the strongest of the general-purpose extrusion alloys that are still easy to weld and machine. That is why it is specified for load-bearing angle in machine frames, trailers, walkways, solar mounting and marine fittings, while the softer 6063 is preferred for trims, glazing beads and other visible architectural work where finish matters more than strength.
Angle is ordered by leg length A, leg length B and thickness t. Equal-leg angle (A = B) is the most common; unequal-leg angle puts more material in one direction and is used where one face carries the fixing and the other provides stiffness. Two corner forms exist: the Aluminum Association / ASTM B308 structural angle, with a radiused root fillet and rounded toes, and the "sharp corner" or architectural angle, with square inside and outside corners.
Types of 6061 angle and when to use each
Unequal-leg angle
One leg longer than the other, for example 3 × 2 in or 100 × 50 mm. Useful where a wide face is needed for bolting or welding and the narrow leg acts as a stiffener.
Sharp-corner angle
Square inside and outside corners for edge protection, framing that must sit flush and parts that will be machined. Slightly lighter than radiused angle of the same nominal size.
Radiused or bulb angle
Generous inside radius, sometimes with a bulb on the toe. The radius reduces stress concentration at the root, which helps fatigue life in vibrating structures.
Slotted and punched angle
Angle supplied with pre-punched slots or holes for adjustable bolted racks, cable support and shelving. Punching is done after extrusion, to a drawing.
Custom angle profiles
Non-standard legs, uneven thicknesses, serrations or lips can be extruded on a dedicated die. Worth it for repeat volumes, where a lighter purpose-made section saves material.
6061 chemical composition
All 6061 angle, whatever the standard, follows the registered composition limits below (Aluminum Association, ASTM B221, EN 573-3). The mill test certificate reports the actual analysis for each cast.
| Element | Min % | Max % |
|---|---|---|
| Silicon (Si) | 0.40 | 0.80 |
| Iron (Fe) | — | 0.70 |
| Copper (Cu) | 0.15 | 0.40 |
| Manganese (Mn) | — | 0.15 |
| Magnesium (Mg) | 0.80 | 1.20 |
| Chromium (Cr) | 0.04 | 0.35 |
| Zinc (Zn) | — | 0.25 |
| Titanium (Ti) | — | 0.15 |
| Others, each / total | — | 0.05 / 0.15 |
| Aluminium (Al) | Remainder |
Magnesium and silicon form the Mg2Si precipitates that give 6061 its heat-treated strength. Copper adds strength, and chromium controls grain structure, which is why 6061 extrusions are less prone to coarse surface grain than leaner 6xxx alloys.
Mechanical properties of 6061 angle by temper
For design, use the specified minimums of the order standard, not typical values. The ASTM B221 and EN 755-2 minimums for extruded 6061 are almost identical, so a T6 angle certified to either is interchangeable for most structural purposes.
| Temper | Tensile strength, min | Yield strength (0.2 %), min | Elongation, min | Notes |
|---|---|---|---|---|
| O | ≤ 150 MPa (max) | ≤ 110 MPa (max) | 16 % | Annealed, for severe forming |
| T4 / T4511 | 180 MPa / 26 ksi | 110 MPa / 16 ksi | 16 % | Formable; can be aged to T6 afterwards |
| T6 / T6511, wall ≤ 6.3 mm | 260 MPa / 38 ksi | 240 MPa / 35 ksi | 8 % | Standard structural temper |
| T6 / T6511, wall > 6.3 mm | 260 MPa / 38 ksi | 240 MPa / 35 ksi | 10 % | Thicker legs |
| T6 typical values | 310 MPa / 45 ksi | 276 MPa / 40 ksi | 12 % | Approx. 95 HB |
Minimums summarised from ASTM B221 and EN 755-2; the governing edition and thickness band appear on the mill certificate. T6511 is T6 with controlled stretching and minor straightening permitted.
Physical properties (T6)
- Density
- 2.70 g/cm³ (0.0975 lb/in³)
- Modulus of elasticity
- 68.9 GPa (10,000 ksi)
- Shear strength, typical
- 207 MPa (30 ksi)
- Thermal expansion
- 23.6 µm/m·°C (20 – 100 °C)
- Thermal conductivity
- 167 W/m·K
- Electrical conductivity
- About 43 % IACS
6061 angle sizes and weight per foot and metre
Weights below are calculated from the sharp-corner cross-section, area = t × (A + B − t), multiplied by the density of 6061. Structural angles with root fillets weigh one to five per cent more than these figures, so use the supplier's catalogue weight for freight and the calculated weight for quick estimates.
| A × B × t (in) | Area (in²) | Weight (lb/ft) | Weight (kg/m) |
|---|---|---|---|
| 1 × 1 × 0.125 | 0.234 | 0.27 | 0.41 |
| 1 × 1 × 0.25 | 0.438 | 0.51 | 0.76 |
| 1.5 × 1.5 × 0.125 | 0.359 | 0.42 | 0.63 |
| 1.5 × 1.5 × 0.25 | 0.688 | 0.80 | 1.20 |
| 2 × 2 × 0.125 | 0.484 | 0.57 | 0.84 |
| 2 × 2 × 0.1875 | 0.715 | 0.84 | 1.25 |
| 2 × 2 × 0.25 | 0.938 | 1.10 | 1.63 |
| 2 × 2 × 0.375 | 1.359 | 1.59 | 2.37 |
| 2.5 × 2.5 × 0.25 | 1.188 | 1.39 | 2.07 |
| 3 × 2 × 0.25 | 1.188 | 1.39 | 2.07 |
| 3 × 3 × 0.25 | 1.438 | 1.68 | 2.50 |
| 3 × 3 × 0.375 | 2.109 | 2.47 | 3.67 |
| 4 × 3 × 0.375 | 2.484 | 2.91 | 4.33 |
| 4 × 4 × 0.25 | 1.938 | 2.27 | 3.37 |
| 4 × 4 × 0.5 | 3.750 | 4.39 | 6.53 |
| 5 × 5 × 0.5 | 4.750 | 5.56 | 8.27 |
| 6 × 4 × 0.5 | 4.750 | 5.56 | 8.27 |
| 6 × 6 × 0.5 | 5.750 | 6.73 | 10.02 |
| 8 × 8 × 0.75 | 11.438 | 13.38 | 19.92 |
Metric angle is widely stocked in Europe, the Middle East and Asia. Common sizes and calculated masses:
| A × B × t (mm) | Area (mm²) | Mass (kg/m) |
|---|---|---|
| 20 × 20 × 2 | 76 | 0.205 |
| 20 × 20 × 3 | 111 | 0.300 |
| 25 × 25 × 3 | 141 | 0.381 |
| 30 × 30 × 3 | 171 | 0.462 |
| 40 × 40 × 4 | 304 | 0.821 |
| 40 × 40 × 5 | 375 | 1.012 |
| 50 × 50 × 5 | 475 | 1.282 |
| 50 × 50 × 6 | 564 | 1.523 |
| 60 × 60 × 6 | 684 | 1.847 |
| 75 × 50 × 6 | 714 | 1.928 |
| 75 × 75 × 8 | 1136 | 3.067 |
| 80 × 80 × 8 | 1216 | 3.283 |
| 100 × 50 × 8 | 1136 | 3.067 |
| 100 × 100 × 10 | 1900 | 5.130 |
| 120 × 120 × 10 | 2300 | 6.210 |
| 150 × 150 × 12 | 3456 | 9.331 |
Typical supply range
- Leg length
- About 10 mm (3/8 in) up to 200 mm (8 in); larger on special dies
- Thickness
- About 1.5 mm (1/16 in) up to 25 mm (1 in)
- Lengths
- Mill lengths of 3 – 6 m (12, 20 or 24 ft), or cut to length
- Finish
- Mill, clear or colour anodised, powder coated, brushed
Standards and international designations
| Standard / system | What it covers |
|---|---|
| ASTM B221 / B221M | Extruded bar, rod, wire, profiles and tubes, including 6061 angle in all tempers |
| ASTM B308 / B308M | 6061-T6 standard structural profiles (angles, channels, I-beams, tees, zees) with Aluminum Association dimensions |
| AMS-QQ-A-200/8 and AMS 4150 | Aerospace and defence extrusions in 6061 |
| EN 755-2 / EN 755-9 | European mechanical properties and dimensional tolerances for extruded profiles |
| ANSI H35.2 | Dimensional tolerances for ASTM aluminium mill products |
| Designations | UNS A96061 · EN AW-6061 (AlMg1SiCu) · Werkstoff 3.3211 · JIS A6061 · ISO AlMg1SiCu; the old British designation H20 is still seen on drawings |
For structural design, the Aluminum Design Manual (Aluminum Association) and Eurocode 9 (EN 1999-1-1) give allowable or characteristic stresses for 6061-T6, including the reduced strength of welded zones.
Tolerances, straightness and inspection
Unless the drawing states tighter limits, 6061 angle is delivered to the standard tolerance tables: ANSI H35.2 for ASTM orders, EN 755-9 for EN orders. Tolerances depend on the leg length and thickness band, and are tighter for sharp-corner precision angle than for heavy structural angle.
- Leg length and thickness: per the tables of the order standard; precision angle can be agreed to closer limits
- Squareness: the angle between legs is controlled, typically within about ±1° for structural angle
- Straightness and twist: controlled by stretching; T6511 allows minor straightening after stretching
- Cut lengths: saw-cut angle is commonly held to about ±1.5 mm (1/16 in); mill lengths have wider limits
- Certification: EN 10204 3.1 certificate with chemistry, tensile results and temper
Cutting, welding, bending and finishing
Cutting and drilling
Use carbide-tipped saw blades with a negative or low positive hook and a lubricant. Clamp both legs to stop chatter. T6 drills and taps cleanly; deburr all cut edges before assembly or anodising.
Welding
MIG and TIG with ER4043 or ER5356 filler. The heat-affected zone drops to roughly 165 MPa tensile, so put welds away from the most highly stressed sections or size members for the welded strength.
Bending
T6 angle cracks if bent tightly. Bend the leg that is in compression where possible, keep generous radii, or order T4 and age to T6 after forming.
Bolted joints
Use stainless or coated steel fasteners with insulating washers in wet environments to limit galvanic corrosion. Avoid direct contact with copper and carbon steel.
Anodising and coating
6061 anodises well, though the finish is slightly less bright than 6063. Powder coating is common for outdoor frames and solar structures.
Corrosion
Good atmospheric resistance; suitable for coastal structures when anodised or painted. For permanent seawater immersion, use 5xxx plate or 6082/6005A with protection.
Where 6061 angle is used
- Machinery: frames, guards, mounting rails and base structures
- Transport: trailer and truck body framing, rail and bus interiors, roof racks
- Construction: support framing, stair nosings, curtain-wall brackets, handrail posts
- Marine: superstructure framing, walkways and deck fittings, usually anodised or painted
- Energy: solar module mounting, battery racks, cable-tray supports
- Logistics: racking, conveyors and light handling equipment
- Aerospace ground support: stands, platforms and tooling frames
6061 vs 6063 aluminum angle: which to choose
| Property | 6061-T6 angle | 6063-T6 angle |
|---|---|---|
| Tensile strength, min | 260 MPa (38 ksi) | 205 MPa (30 ksi) |
| Yield strength, min | 240 MPa (35 ksi) | 170 MPa (25 ksi) |
| Machinability | Very good | Fair (gummy) |
| Weldability | Good | Good |
| Anodised appearance | Good | Excellent, brighter |
| Typical use | Structural and mechanical | Architectural and decorative |
Pick 6061 when the angle carries load, will be machined, or must keep its section under bolted clamping. Pick 6063 when appearance and cost dominate and loads are light. Where even more strength is needed, 7075 angle offers roughly double the yield of 6061 but cannot be welded structurally.
How to order 6061 angle from Metline
- SpecifyLeg A, leg B, thickness, corner type (structural radius or sharp), temper (T6 or T6511), length and quantity, plus the governing standard.
- Finish and processingMill, anodised or powder coated; cut lengths, punching, drilling or mitring to drawing.
- QuoteWe confirm availability, tolerance, certification and delivery terms (EXW, FOB, CIF or DAP).
- Inspect and documentDimensional and visual check, EN 10204 3.1 certificate, packing list; third-party inspection on request.
- ShipBundled with interleaving and wrapped, in wooden cases or crates for export by sea or air.
References and standards
- ASTM B221 – Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes
- ASTM B308/B308M – Aluminum-Alloy 6061-T6 Standard Structural Profiles
- EN 755-2 – Extruded rod/bar, tube and profiles: mechanical properties
- The Aluminum Association – Aluminum Design Manual
- ANSI H35.2 – Dimensional Tolerances for Aluminum Mill Products
6061 aluminium angle: frequently asked questions
How much does 6061 aluminium angle weigh?
Multiply the cross-section area by the density. For a sharp-corner angle the area is t × (A + B − t). A 2 × 2 × 1/4 in angle is about 1.10 lb/ft, and a 50 × 50 × 5 mm angle about 1.28 kg/m. Radiused structural angle weighs slightly more.
Is 6061 angle as strong as steel angle?
Its minimum yield of 240 MPa is close to that of common mild steel, but its stiffness is only about one third. An aluminium angle of the same size deflects about three times as much, so long spans usually need a deeper or thicker section.
What is the difference between 6061-T6 and T6511 angle?
Both have the same strength. T6511 indicates the extrusion was stress-relieved by stretching and may receive minor straightening afterwards, giving better straightness and less movement when machined.
Can 6061 aluminum angle be bent?
Gentle bends are possible in T6, but tight bends crack. For tight radii, order T4 or O temper, form it, then heat-treat to T6.
Can 6061 angle be welded?
Yes, with MIG or TIG using ER4043 or ER5356 filler. Expect lower strength in the heat-affected zone unless the assembly is re-solution treated and aged.
Is 6061 angle suitable for outdoor and coastal use?
Yes. It resists atmospheric corrosion well; anodising or powder coating adds protection near the sea. Isolate it from copper and carbon steel to prevent galvanic attack.
Need 6061 angle cut to length?
Send sizes, temper, finish, quantity and destination. We will confirm availability, certification and a delivered price.
