Aluminum Angles
Aluminum ore is the most commonly found earth metal. The commercial aluminum used to make products, however, must be refined several times through Bayer and electrolytic processes. Processed alumina has physical properties that give it a high strength to weight ratio, as well as non-corrosiveness, non-toxic, non-magnetic, non-combustible, and non-sparking characteristics. Aluminum is 100% recyclable. Aluminum sheets can be formed into aluminum solid angles, aluminum I-beams, aluminum angle trim, and aluminum channel, to list a few. Aluminum never loses its properties making it a nearly ideal material for marine and aircraft to flashlights and containers.
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Design of Aluminum Angles
Aluminum angles are standard extruded L-shaped parts composed of 2 legs that intersect and form a 90 degree angle, essentially they are a length of aluminum bent at a right angle along its long dimension. Aluminum is an ideal metal for the manufacturing of these long, narrow shapes because of its beneficial characteristics such as a high strength-to-weight ratio and excellent corrosion resistance. The legs of the angle are either equal or unequal in length, and often have sharp corners.
We have seen that common metal construction and utility 90-degree angles may be flat, flat with an offset hole, punched (perforated) hole, slotted hole, and slotted offset hole. Angles are available in many sizes and that can be cut to length to job specifications. Angles may be fabricated out of a variety of materials including steel, aluminum, nickel, copper, brass, etc. depending on the use and specifications. They may be heat treated or tempered to increase their strength and durability. And they may also be mill finished or coated (powder coated, anodized, etc.) to ensure they do not rust or corrode in harsh environments (i.e.: weather, chemicals, stress, etc.). Coated angles pieces’ finishes can be painted.
Materials in Angles
These L-shaped components are commonly used in structural support systems. In the building trade the L-shaped component, or rod, is referred to as an aluminum angle iron or aluminum angle bar. Similarly, mechanical engineers consider an aluminum angle iron or aluminum angle bar as any right-angled, L-shaped piece. Steel is the most common metal for angle iron but aluminum is often used because of its non-corrosiveness as well as its strength-to-weight ratio. Angle iron is considered structural material and frequently used for repairs that demand lightweight structural strength. Angle iron comes in varying lengths and sizes. The L-shaped bent metal extends the length of the material, which creates horizontal and vertical flat surfaces that adds strength to the unit, in both directions.
Perforated angles have pre-drilled holes on each leg that allow angles to be attached to other components.
Aluminum Angle Stock
The technical specifications for standard aluminum angle stock include:
Angle 90 Degrees
Aluminum Material
Type 6061 (or 6063) Alloy
Smooth Unpolished Finish
T6 Temper
95 (Typical) Hardness
Technical Standards: ASTM B308, AMS-QQ-A-200
Angle Shapes
The edge shape variations for aluminum angle irons are nearly endless. Many manufacturers customize specific shapes according to specifications. Curved and beveled edges, unequal leg lengths, and hemmed edges are common requests. The L-angle, which is routinely set at 90 degrees (for standard angles) may also be modified. Multiple angles, complex shapes, asymmetric designs are not uncommon. Perforations, cut-outs, and holes may be surface punched. These are typically used with screw, bolt, or hook hardware.
Angle Sizes
Manufacturers can machine, weld, or cut angle iron to a specified length or size. Many distributors have angles readily available in standard aluminum angle sizes, such as:
1 x 1 Aluminum Angle 6061 or 6063 – Thickness 1/8"
2 x 2 Aluminum Angle 6061 – Thicknesses 1/8" – 3/8"
3 x 3 Aluminum Angle 6061 – Thicknesses 1/4" and 1/2"
4 x 4 Aluminum Angle 6061 – Thicknesses 1/4" - 1/2"
Sizes of equal angle legs may be expressed by naming the length of one side: 1/8" x 2" where the 2" is the angle leg or flange and 1/8" is the angle thickness. Angles that have longer sides are typically made of thicker metal and have a thicker root (the area where the bend is). Larger angles can support heavier loads. Standard angle iron pieces are available in lengths 3’ up to 8’. They may be easily cut to length with a chop or hack saw.
Aluminum angle sizes for 6061-T6 and 6063-T52 pieces may be as long as 16’ and 25’ with tapered legs or square corners. Ultra-corrosive-resistant architectural grade 6063-T5 can come in 3’, 6’, 8’, and 12’ cut lengths.
Aluminum Finishes
There are two primary finish types available. Mill finishes are typically polished or buffed. Coatings applied to aluminum angle stock are durable vinyl and can be powder coating, galvanizing, or electroplating (anodizing).
Aluminum pieces are oxidized in a chemical bath to increase surface thickness and strength. This process is anodizing, which is an electrolytic process also used to reduce corrosion. An anodized aluminum angle is significantly stronger and (surface) harder than those that have not been treated. A sealant must be applied to improve the anodized aluminum angle’s wear resistance, however.
Aluminum Extrusion Process
All angles and shapes made of aluminum undergo an extrusion process that creates consistent aluminum sections that are cut and welded together. Two aluminum pieces of same or varying sizes are welded using the tungsten electrode process. Each L-shape is a 90-degree angle per specifications. The extrusion process is the forming of long, constant cross-section structural parts by pushing metal billets through a die at either various temperatures. The various temperatures separate extrusion processes into three different methods: hot extrusion, warm extrusion and cold extrusion. Hot extrusion is for extrusion processes that take place at high temperatures, while warm extrusion takes place at moderately high temperatures and cold extrusion takes place at or very near room temperature. After the extrusion process occurs, the legs of the aluminum angles are often welded together because extruding an L-shape can be difficult. One method of welding used in this process is tungsten inert gas (TIG) welding. An arc welding process, TIG welding utilizes a non consumable tungsten electrode in order to produce the weld. In addition, to obtain the desired strength for structural applications, aluminum angles are often T5 or T6 tempered, a form of heat treatment in which the metal is strengthened when the intermetallic particles are precipitated. Structural aluminum angles are often anodized, a finishing process where the aluminum is oxidized in a chemical bath, which forms a strong outer coating.
Types of Aluminum Angles
Pure aluminum is highly conductive, reflective, and non-corrosive, but has minimal strength. Aluminum alloys have been developed with desired attributes that meet particular uses and specifications. The most common aluminum grades used for structural parts and angles are 6061 and 6063. Each contains magnesium and silicon alloys.
6061 Aluminum Angle
Which is alloyed with magnesium and silicon, is the most common material for structural applications. However, 6063 aluminum, which is also alloyed with magnesium and silicone, is another common material used in the manufacturing of aluminum angles, due to its good mechanical characteristics such as moderate strength and exceptional finishing properties. 6061 aluminum angles are generally characterized by rounded corners, while 6063 aluminum angles have sharp corners that reflect their typical applications.
6061 aluminum alloy is the most commonly used angle alloy because of its strength, temper (heat treatability), and ability to be welded. Its primary alloy ingredients are magnesium and silicon.
6061 aluminum angle has rounded corners and is mainly used for structural applications. It can effectively be anodized by adding a layer of protective finish. 6061 aluminum angle has above average corrosion resistance, is non-magnetic, is relatively easy to machine and weld, and resists stress and cracking.
A 6061-T6 structural aluminum angle, for example, has twice the strength of a 6063-T52 architectural aluminum angle. Similarly, a 6061-T6 American Standard aluminum I-beam is often used in aircraft construction.
6061-T6 Aluminum Physical and Mechanical Properties:
Max. Tensile Strength: 45,000 psi
Yield Strength: 40,000 psi
Brinell Hardness: 95
Rockwell Hardness: B60
6063 Architectural Aluminum Angle
Architectural aluminum has a surface finish far smoother than other commercially-available alloys. It also has less strength. The 6063 aluminum angle has sharp/square corners and is mainly used where surface finish, rather than strength, is the primary focus. 6063-T52 aluminum is a softer and more easily formed alloy than the 6061 aluminum alloy. For example, the 6063 aluminum angle only has half the strength of the 6061 structural aluminum angle. 6063-T52 is well-suited for outdoor aluminum angle trim due to corrosion resistance nature.
The anodizing process increases the 6063 angle’s strength as well as its extreme resistance to corrosion. The strong oxidized coat replaces and smooths the original aluminum surface during the chemical process.
Overall, 6063 aluminum is rated: Excellent for anodizing; good for forming and cold working; fair for machining.
6063-T52 Aluminum Minimum Properties:
Max. Tensile Strength: 27,000 psi
Yield Strength: 21,000 psi
Brinell Hardness: 60
Slotted Aluminum Angle
A slotted aluminum angle is machine pressed and hole-punched from aluminum sheets. The strips are produced in standard lengths. The slotted angles are formed by longitudinally folding the metal strips to form the 90-degree right angle.
The slotted (or pierced) aluminum angle iron has holes punched at specified/standard distances along both sides of the part. The holes are typically spaced one inch (2.54 cm) apart (measured center to center). The holes are oval-shaped, which accommodates varying degrees of stress imposed on the finished product. Slotted angle sections are typically used for vertical commercial shelving sections. Slotted aluminum angles make the shelving easy to assemble using nuts and bolts. A slotted angle system is lightweight, architectural grade consisting of reusable metal strips with uniformly punched elongated holes.
Perforated Aluminum Angle
Perforated aluminum angles are made from perforated sheet aluminum that is extremely corrosion resistant, heat and light reflective, and are recommended for applications requiring formability and ductility. A variety of surface finishes may be applied. Perforated aluminum is routinely anodized to improve strength and color. For most applications, however, no protective coating is necessary. The material functions well at low-temperatures. Ductility is maintained and overall strength increases at temperatures below 0 F degrees. The aluminum alloy begins to lose strength as temperatures climb above 400F degrees.
Perforated sheets come in widths up to 60 inches. The aluminum sheet is perforated using lasers, die/punch presses, or rotary pinned perforation rollers. Hole patterns (ovals, round, squares and rectangles, triangles, and slots as narrow as 1/64 in. can be punched. Patterns and shapes may also be stamped or punched. Perforated aluminum is more malleable and a lighter weight metal compared to other metals (steel, brass, copper, etc.). Similar to slotted angles, a perforated aluminum angle is formed from the perforated aluminum sheet by longitudinally folding the metal strips into a 90 degree right angle part per specifications.
A perforated aluminum angle is chemical and weather resistant, and extra high strength. Anodized angles are well-matched with extruded aluminum components. Perforated aluminum materials and angles perform effectively in extreme marine, transport, and industrial environments.
Perforated Aluminum Angle
Manufacturer and distributor aluminum angle price(s) for equal leg and unequal leg structural and architectural type angles are based on the part’s overall dimensions:
Leg A x Leg B x Wall Thickness
Cut Length
Alloy and Temper
Finish (Anodized)
Aluminum Angle Applications
Among the subcategories of aluminum angles are extruded aluminum angles, which are mostly found within the construction, building and engineering industries as structural components. Aluminum angles are used as framing, railings, posts, supports, hangers, brackets, reinforcements, stiffeners, flanges, collars, window frames, trim, and bars. In addition to structural applications, aluminum angles are also widely used for engineering applications such as in rail cars, ground transportation systems, scaffolding and in cooling towers.
Aluminum 6061-grade angles are twice as strong as 6063 architectural-grade angles. They are corrosion resistant, non-magnetic, and resist stress and cracking. They are extensively used for heavy duty operations that require lighter weight components such as scaffolding, furniture, truck trailers, machine parts, ship construction, and transmission towers.
Aluminum 6063-grade angles are extensively used for architectural molding and trim, furniture, window and door construction, etc. They add structural strength and may be attached to wood frames to add support and stability. They are typically used for constructing bed frames, bicycle and storage racks, and other utility functions.
Slotted and perforated angles are generally used in garage storage racks and door tracks, shelving, and corner bracing.
Angles that can be easily formed and welded may be utilized as fence construction components. They may also be used to provide structural strength support for window and door frames set in masonry. Angles support the masonry block wall weight above the window/door opening. Shelves may be installed in a masonry wall using the same principle.
Angle Standards and Specifications
All angles must meet ASTM (American Society for Testing and Materials) specifications for this type of aluminum product. In general, ASTM B308 addresses equal leg as well as unequal leg aluminum structural angles.
ASTM B221 specifications apply to 6061-T6 structural (aluminum) angles and 6063-T52 (sharp corner) aluminum architectural angles.
Tempered angles (T5 or T6) are heat-treated to increase the strength of the aluminum material.
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Aluminum Angle Informational Video