Structural steel angle bar

01

Understand the shape and size classes

Nucor, a US steelmaker, describes a steel angle as a structural component with an L-shaped cross-section whose two legs form a 90-degree angle, with equal or unequal legs. It lists angles, channels, rounds, squares and flats among the structural shapes in its merchant bar range, and says it makes multiple sizes, including large angles. Angles are used in construction, engineering and other industries for structural support, corner protection and fastening. [1]

Nucor quotes the Steel Manufacturers Association's product classes. Light shapes are carbon and HSLA angles, channels, beams, Ts, Zs and other shapes with no dimension greater than 3 in, including shapes with one or more dimensions equal to 3 in. Structural angles and channels are carbon and HSLA angles and channels with at least one dimension greater than 3 in. [1]

Editorial calculation: 3 in is 76.2 mm. For shipbuilding, Nucor lists angle bar in ABS Grade A at 6.4 mm (0.25 in) and adds that products and grades vary by mill. [1]

Give the supplier the leg sizes and thickness (equal or unequal), the steel specification and grade, the length (stock or cut), the straightness and dimensional tolerances, the surface condition or coating (for example galvanised or primed), any punching, drilling or cutting, the quantity, and the mill certificate and inspection required.

02

Choose the steel specification and grade

ASTM A36/A36M covers carbon steel shapes, plates and bars of structural quality for riveted, bolted or welded construction of bridges and buildings and for general structural purposes. When the steel is to be welded, a welding procedure suitable for the grade and intended service is to be used. [2]

ASTM A572/A572M covers five grades of high-strength low-alloy structural steel shapes, plates, sheet piling and bars. Grades 42 [290], 50 [345] and 55 [380] are intended for riveted, bolted or welded structures. Grades 60 [415] and 65 [450] are intended for riveted or bolted bridges, or for riveted, bolted or welded construction in other applications. A588/A588M may not be substituted without agreement. [3]

ASTM A6/A6M sets the general requirements that apply to rolled structural steel bars, plates, shapes and sheet piling under product specifications such as A36, A572 and A588, unless the product specification says otherwise. [4]

Editorial calculation: 50 × 6.895 ≈ 345, so the bracketed figures are the grade numbers converted from ksi to MPa.

03

Consider higher-strength and weathering grades, and check the marking

ASTM A529/A529M covers high-strength carbon-manganese steel shapes, plates and bars of structural quality in Grade 50 [345] and Grade 55 [380]; for shapes it applies to flange or leg thicknesses up to 1½ in [40 mm], and the steel must be killed. ASTM A588/A588M covers high-strength low-alloy shapes, plates and bars with atmospheric corrosion resistance substantially better than carbon structural steels, intended for welded bridges and buildings where weight saving or durability matter, usable bare (unpainted) when properly exposed, up to 8 in [200 mm] thick. [5] [6]

Under ASTM A6/A6M, which A36, A572, A529 and A588 all reference, finished products are legibly marked, bundled and tagged with the specification designation, grade, heat number, size and thickness, and the maker's name, brand or trademark; tension tests and chemical analysis confirm tensile strength, yield strength, elongation and composition. Check the tag against the mill certificate on delivery. [4] [5] [6]

Editorial calculation: 1½ in is 38.1 mm (ASTM rounds it to 40 mm in the metric designation), so an angle with legs thicker than that falls outside A529 and needs A572 or another specification. [5]

04

Leg lengths, leg thickness, grade, corrosion resistance and marking

Leg thickness decides grade eligibility as well as weight: ASTM A529 applies to shapes with leg thickness up to 1½ in [40 mm]. [5]

05

Size class, ASTM specification, welding and marine grade for an angle order

Nucor separates light shapes (≤3 in) from structural angles (>3 in); state the class of your sizes together with the ASTM specification and grade. [1]

06

Send the size, grade and processing data together

Paste it into your enquiry below or into an email to a maker, then replace every bracket.

Size: [leg × leg × thickness; equal or unequal]
Grade: [ASTM A36; A572 Gr 50; EN/GB equivalent]
Length: [stock; cut length; tolerance]
Finish: [black; galvanised; primed]
Processing: [cutting; punching; drilling]
Quantity: [tonnes or pieces]
Documents: [mill test certificate; inspection]

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