Product code representation method for non-ferrous metals and their alloys
Product codes for nonferrous metals and their alloys are crucial identifiers for identifying their composition, properties, and uses. China’s national standard GB/T 340-2008 standardizes these codes. Through a combination of letters, numbers, and symbols, these codes clearly reflect the material’s category, grade , state, and product form, providing a standardized basis for production, use, and trade. Understanding these codes facilitates accurate material selection, ensures product quality, and improves production efficiency, possessing significant practical value in aerospace, electronics, and automotive manufacturing.
The category codes for non-ferrous metals and their alloys are represented by uppercase Latin letters, clearly distinguishing different metal categories and facilitating quick identification of material properties. Common category codes include: “T” for pure copper (red copper), such as T2 for Grade 2 pure copper; “H” for brass, a copper-zinc alloy, such as H62 for ordinary brass with a 62% copper content; “Q” for bronze, including tin bronze and aluminum bronze, such as QSn4-3 for tin bronze with a 4% tin and 3% zinc content; “B” for cupronickel, a copper-nickel alloy, such as B19 for ordinary cupronickel with a 19% nickel content; “L” for aluminum and aluminum alloys, such as L2 for Grade 2 industrial pure aluminum; “Z” for zinc and zinc alloys, such as Zn99.99 for zinc with a purity of 99.99%; and “Mg” for magnesium and magnesium alloys, such as Mg-Al-Zn for an aluminum-zinc magnesium alloy. These letter codes are the basis of product codes, directly reflecting the core components of the materials, and are the most critical identification elements in the code system.
The method of expressing alloy grades is based on the category code, and the composition content or alloy series is further clarified by numbers. Different categories have their own rules. Pure metal grades are designated by numbers to indicate purity, such as T1, T2, and T3 for Grade 1, Grade 2, and Grade 3 pure copper, respectively. The higher the number, the lower the purity. T1 has a copper content of ≥99.95%, and T2 ≥99.90%. Brass grades are designated by the percentage of copper content, such as H68 for 68% copper and HNi65-5 for nickel brass containing 65% copper and 5% nickel. Bronze grades are designated by the symbols and contents of the main alloying elements, such as QAl9-4 for aluminum bronze containing 9% aluminum and 4% iron, and QBe2 for beryllium bronze containing 2% beryllium. Aluminum alloy grades are designated by four digits in accordance with the national standard GB/T 16474-2011, such as 6061 for Al-Mg-Si aluminum alloy. The first digit “6” represents the alloy series, and the last three digits indicate the specific grade. These digital codes accurately reflect the composition ratio of the alloy and are an important basis for material selection and performance judgment.
The product status code is used to indicate the processing status or heat treatment status of non-ferrous metals and their alloy products. It is expressed by capital letters and numbers and directly affects the mechanical properties and processing properties of the material. Common temper codes include: “F” for as-cast, the state of the casting before pressure working, such as ZAlSi12F for as-cast aluminum-silicon alloy; “O” for annealed, characterized by good plasticity and low strength, suitable for deep drawing, such as H62-O for annealed H62 brass; “Y” for hard, the cold-work-hardened state, characterized by high strength and low plasticity. The numerical suffix indicates the degree of hardening, such as Y1, Y2, and Y for low-hard, medium-hard, and hard, and H62-Y for hard H62 brass; “T” for heat-treated, commonly used aluminum alloys, such as T6 for solution-treated and artificially aged, 6061-T6 being a commonly used high-strength aluminum alloy; and “M” for soft, the state with the lowest strength after annealing, such as L2-M for soft industrial-pure aluminum. Tempering codes are an integral part of product designations. The same grade of material can exhibit significant performance differences in different tempers, so accurate labeling is essential.
Product form codes indicate the shape and specifications of nonferrous metal and alloy products. These codes are written in lowercase letters and follow the grade and temper codes, making the codes more specific. Common product form codes include: “p” for plate, such as H62-Y4p, indicating hardened H62 brass plate; “t” for strip, such as QSn6.5-0.1-Yt, indicating hardened tin bronze strip; “s” for bar, such as 6061-T6s, indicating 6061 aluminum alloy bar in the T6 temper; “w” for wire, such as L2-Mw, indicating soft industrial pure aluminum wire; “g” for pipe, such as B19-Yg, indicating hardened white copper pipe; “z” for casting, such as ZCuSn10Pb1z, indicating tin bronze casting; and “j” for forging, such as 2A12-T4j, indicating 2A12 aluminum alloy forging in the T4 temper. The product form code is closely integrated with the actual application scenario. For example, plates are mostly used for stamping parts, bars are mostly used for machining, and pipes are mostly used in piping systems. Clear form codes can avoid material selection errors and improve production efficiency.
A complete product code for nonferrous metals and their alloys consists of a category code, a grade, a condition code, and a product form code. For example, “QSn4-3-Yt” designates hard (Y) tin bronze (QSn) strip (t) containing 4% tin and 3% zinc; “6061-T6s” designates 6061 aluminum alloy bar in the T6 condition; and “H62-O-p2mm” designates 2mm thick annealed H62 brass plate (thickness may be specified as an additional parameter). These codes must be used in a standardized manner in product identification, design drawings, and procurement contracts. For example, a mechanical design drawing specifying “Shaft sleeve: QAl9-4-T6s φ50×500” clearly defines the material grade, condition, and specifications, providing a clear basis for production and inspection. Understanding these code notations not only ensures accurate understanding of material information but also avoids quality issues caused by misinterpretation of these codes. This knowledge is essential for those engaged in nonferrous metal processing and application.
