Complete Process, Key Technologies, and Industry Trends of Mold Base Manufacturing

Mold base manufacturing is a complex process that transforms steel into high-precision mold skeletons, involving precision machining, heat treatment, and strict quality control. Based on the latest industry standards and manufacturing practices, here is a comprehensive overview of the complete process, key technologies, and industry trends of mold base manufacturing.

I. Core Process of Mold Base Manufacturing

Mold base manufacturing generally follows a set of standardized procedures to ensure the fit precision and overall strength of all components. Below is a typical production process for a quenched and tempered die-casting mold base.

1. Cutting and Rough Machining

Steel is initially cut (blanking) according to design dimensions, with machining allowance reserved (typically 8-10mm in length, width, and thickness). Rough milling of six sides follows, laying the foundation for subsequent processes.

2. Quenching and Tempering (Heat Treatment)

This is a critical heat treatment process to ensure mold base strength and stability. Materials such as 50# steel are generally quenched and tempered to HRC 28-32 to eliminate internal stress and improve comprehensive mechanical properties.

3. Finish Machining

After quenching and tempering and cooling, secondary rough milling and precision grinding are performed.

• Precision Grinding: The top and bottom surfaces of plates are precision-ground using grinding machines to ensure plate thickness tolerance (e.g., ±0.05mm) and parallelism.

• CNC Finish Milling: All features of the mold base, such as pockets, holes, guide pillar holes, and cooling channel ports, are precisely machined using CNC machining centers.

4. Surface Treatment and Detail Machining

Chamfers (e.g., C2-C5) are added to the edges and corners of the mold base, and threaded holes are tapped.

5. Final Assembly and Inspection

All components, including the moving half, fixed half, guide pillars, guide bushings, and ejector plates, are assembled. Before shipment, a full inspection is conducted, focusing on dimensional accuracy, completeness of components, and the absence of missing features (e.g., vent grooves, ejector pin holes).

II. Key Technologies and Technical Points

The performance and lifespan of a mold base largely depend on material selection and machining precision.

1. Material Selection

Choosing the right steel according to the mold‘s application and cost is critical.

• Mold Base Main Body: 45# steel, 50# steel, or P20 pre-hardened steel are commonly used, requiring good machinability and certain strength.

• High-demand Components: For large die-casting molds or high-life molds, hot-work die steels such as H13 are selected for their better thermal fatigue strength and toughness.

2. Precision Control

• Machining Equipment: Leading companies in the industry generally equip dozens or even hundreds of CNC machining centers, including 5-axis simultaneous machining centers, to handle complex structures.

• Inspection Methods: 100% full inspection is performed using coordinate measuring machines (CMM) to ensure critical geometric tolerances such as parallelism and perpendicularity. For example, parallelism of high-end mold bases can be controlled within 0.01mm/m.

3. New Industry Standard

China officially implemented the national standard GB/T 44530-2024 “Die-casting dies — Mold bases” on April 1, 2025. This standard unifies the types, dimensions, technical requirements, and marking methods for die-casting mold bases, filling a gap in the field and providing an authoritative basis for design, manufacturing, and inspection, thereby helping to improve the standardization and normalization of the industry.

III. Industry Trends and Representative Companies

Currently, the mold base industry is moving toward larger sizes, higher precision, and greater intelligence.

1. Large-scale Integrated Die-casting

With the surging demand for lightweight structural components (such as front/rear underbodies and battery housings) in new energy vehicles, ultra-large integrated die-casting mold bases have become a technological high ground. These mold bases are extremely large in size and demand very high rigidity and precision.

• Representative Company: Jiangsu ShuaiGang Mold Base Manufacturing Co., Ltd. is a leader in this field, cooperating with automakers such as Tesla, NIO, and Li Auto, and has completed nearly 70% of the global NEV integrated die-casting projects.

2. Intelligence and Rapid Delivery

To improve efficiency and response speed, leading companies are building digital production bases.

• Representative Company: Guangdong Dexin Mould Steel Industrial Co., Ltd. has introduced more than 200 precision machine tools and FMS flexible production lines, achieving fully automated mold base machining, assembly, and inspection, enabling 48-hour emergency delivery for standard mold bases.

In summary, mold base manufacturing is a technology-intensive industry. From complying with new national standards like GB/T 44530-2024, to applying large-scale CNC and automated production lines, and to meeting the stringent requirements of integrated die-casting for new energy vehicles, all demonstrate the industry’s continuous pursuit of precision, efficiency, and innovation.