Angle steel, often referred to as angle iron, is a long strip of steel with sides that are perpendicular to each other. Angle steel can form various load-bearing components according to different structural needs or serve as connections between components. It is widely used in various building structures and engineering structures, such as beams in engine rooms, bridges, transmission towers, lifting and transporting machinery, ships, industrial furnaces, reaction towers, container frames, cable trench supports, power pipelines, busbar bracket installations, and warehouse shelves.
Angle steel mainly comes in two types: equal angle steel and unequal angle steel. Unequal angle steel can be further divided into two types: those with unequal edge thickness and those with equal edge thickness.
As the name suggests, equal angle steel has equal side lengths. Its specifications are expressed in millimeters as side width * side width * side thickness. For example, 30 * 30 * 3 indicates equal angle steel with a side width of 30mm and a side thickness of 3mm. It can also be represented by a model number (numerical value), where the model is the centimeter measurement of the side width. A symbol "∠" can be added in front of the angle steel model, and a "#" symbol can be added to the upper right of the model, for example, ∠30#. The range of equal angle steel specifications is from 2# to 20#.
Unequal angle steel is long steel with an L-shaped cross-section, with sides that are perpendicular to each other and variable in width. Its specifications are expressed in millimeters as long side width * short side width * side thickness, for example, "L30 * 20 * 3", indicating unequal angle steel with a long side width of 30mm, a short side width of 20mm, and a side thickness of 3mm. It can also be represented by a model number (numerical value), where the model is expressed as a fraction, with the numerator being the centimeter measurement of the long side width, and the denominator being the centimeter measurement of the short side width, for example, "L3/2#", where 3 is the long side's centimeters and 2 is the short side's centimeters. The range of unequal angle steel is from 2.5/1.6# to 20/12.5#.
China imports and exports a certain amount of angle steel, mainly imported from Japan and Western Europe. Exports are primarily to Hong Kong and Macau, Southeast Asia, Latin America, and Arab countries. Major exporters are steel plants (rolling mills) in provinces and cities like Liaoning, Hebei, Beijing, and Shanghai.
Standards specify the surface quality of angle steel, generally requiring no harmful defects such as delamination, scars, or cracks. Standards also define the allowable range of deviations in the geometric shape of angle steel. Typically, this includes bending degree, side width, side thickness, top angle, theoretical weight, etc., and specifies that angle steel should not have noticeable twists.
The chemical composition of angle steel belongs to the series of rolled steel for general structural use. The main verification indicators are C (Carbon), Mn (Manganese), P (Phosphorus), and S (Sulfur). The content varies depending on the grade, with general ranges being C<0.22%, Mn: 0.30-0.65%, P<0.060%, and S<0.060%.
Tensile Test Methods: Common standard inspection methods include GB/T228-87, JISZ2201, JISZ2241, ASTMA370, ГОСТ1497, BS18, DIN50145, etc.
Bending Test Methods: Common standard inspection methods include GB/T232-88, JISZ2204, JISZ2248, ASTME290, ГОСТ14019, DIN50111, etc.
The main inspection items for evaluating the performance of angle steel are tensile tests and bending tests. Indicators include yield point, tensile strength, elongation, and bending qualification.
The weight per meter is calculated as 0.00785 * (side width + side width - side thickness) * side thickness. For example, for 50*5 angle steel: (50 + 50 - 5) * 5 * 0.00785 = 3.73 (this method can only roughly calculate the weight of angle steel, the actual weight should refer to the hardware manual).
