1, The mold standard system of the International Organization for Standardization (ISO)
ISO is the most influential standardization organization in the world, and its mold standards are developed by TC 29/SC Subcommittee 8 (Stamping and Forming Mold Subcommittee), covering the technical requirements for standard parts of three major types of molds: stamping dies, plastic molds, and die-casting molds. As of 2024, ISO has released 48 effective mold standards, with core contents including:
Terminology and Dimensional Specifications: ISO 17672 "Mold Terminology" unifies the terminology definitions in the global mold industry to avoid communication errors caused by language differences. For example, clarifying the terminology of key components such as "guide column", "guide sleeve", and "inclined top" provides a foundation for cross-border collaboration.
Material performance requirements: ISO 4957 "Technical delivery conditions for tool steel" specifies the chemical composition, heat treatment process, and mechanical performance indicators of mold steel. For example, it is required that the hardness of plastic mold steel reach HRC 28-32 to ensure a balance between wear resistance and toughness; The thermal fatigue strength of die-casting mold steel needs to meet the requirement of 5000 cycles without cracks to adapt to high temperature and high pressure conditions.
Safety and environmental standards: ISO 13849 "General rules for the design of mechanical safety control systems" requires mold design to integrate safety interlock devices to prevent operators from accidentally touching hazardous areas. For example, car cover molds need to be equipped with photoelectric sensing devices that automatically shut down when human proximity is detected.
Industry case: Apple's iPhone shell mold adopts ISO certified 1.2344 (H13) hot work mold steel, which has a hardness of HRC 52 after vacuum quenching treatment and can withstand high temperature injection pressure of 200 ℃. The service life of a single set of molds exceeds 500000 times, significantly reducing the cost of mold replacement.
2, The Mold Standard System of the European Committee for Standardization (CEN)
The EN standards developed by CEN focus on the quality of molded products and device safety. Among its 12 mold related standards, the following two categories have particularly strict material requirements:
The standard for forging dies and die-casting molds: EN 12543 "Safety Requirements for Die Casting Molds" stipulates that mold materials must pass a -40 ℃ low-temperature impact test to ensure toughness even in cold environments. For example, the BMW engine cylinder body die-casting mold uses EN standard certified 1.2367 (H11) steel, which can still withstand a die-casting force of 1500 tons in an environment of -30 ℃.
Dimensional tolerance standards for formed parts: EN 10243 "Dimensional tolerances for metal stamping parts" divides tolerance levels into F (precision level), M (medium level), and P (coarse level), requiring the linear expansion coefficient of mold steel to be lower than 12 × 10 ⁻⁶/℃ to reduce the impact of thermal deformation on dimensional accuracy. For example, the Bosch fuel injection system mold adopts EN standard certified 1.2083 (420 stainless steel), with a linear expansion coefficient of only 10.5 × 10 ⁻⁶/℃, ensuring that the nozzle diameter tolerance is controlled within ± 0.005mm.
Industry case: The shell mold of Siemens Medical CT machine adopts EN standard certified 1.2738 (P20+Ni) pre hardened steel with a factory hardness of HRC 30-34, which can be directly processed without heat treatment, avoiding the problem of excessive assembly clearance between the shell and internal components caused by thermal deformation.
3, The mold standard system of the American Society for Testing and Materials (ASTM)
The ASTM standard is known for its material performance testing methods. In its mold related standards, the following two categories have industry guidance significance for material requirements:
General Specification for Tool Steel: ASTM A681 "General Specification for Tool Steel" divides mold steel into three categories: cold work steel, hot work steel, and plastic mold steel, and specifies core indicators such as hardness, toughness, and wear resistance for each type of steel. For example, the impact toughness of cold work die steel is required to be ≥ 20J/cm ² to adapt to high stress conditions such as punching and stretching.
The heat treatment process standard for mold steel: ASTM A370 "Test Method for Mechanical Properties of Steel Products" specifies in detail the process parameters such as quenching temperature and tempering time for mold steel. For example, it is required that the quenching temperature of H13 steel be controlled between 1020-1050 ℃, and the tempering temperature be carried out in two stages (550 ℃+480 ℃) to obtain the best comprehensive mechanical properties.
Industry case: Tesla's integrated die-casting body mold adopts ASTM certified 8407 (H13 modified steel), which has a hardness of HRC 54 after special heat treatment. Its thermal fatigue resistance is 30% higher than traditional H13 steel, and it can withstand continuous impact of 6 times per minute on a 6000 ton die-casting machine.
4, The practical application of international standards in the field of consumer electronics
The material requirements for consumer electronics shell molds combine precision and functionality, and international standard application cases include:
Mobile phone frame mold: The Samsung Galaxy S series frame mold is made of ISO certified 1.2316 (420 high acid resistant steel), and after PVD coating treatment, the surface hardness reaches HV2000, which can resist sweat corrosion. At the same time, it has passed the EN standard certified low-temperature impact test to ensure that it can maintain toughness in an environment of -20 ℃.
Laptop shell mold: The Lenovo ThinkPad shell mold uses ASTM certified 718AH (P20+Ni pre hardened steel) with a factory hardness of HRC 33-37, which can be processed directly without heat treatment to avoid the problem of excessive clearance between the shell and keyboard assembly caused by thermal deformation.
Wearable device shell mold: The Apple Watch shell mold is made of ISO certified S136 (420 stainless steel), which has undergone vacuum quenching treatment to achieve a hardness of HRC 50. At the same time, it has passed the salt spray test certified by CEN standards (96 hours without rust), ensuring long-term use in humid environments without rusting.
