Stamping and punching molds, also referred to as dies, are used in the manufacturing process to shape or cut metal sheets. The common materials for these molds vary in durability, thermal conductivity, wear resistance, and other properties. Here are some typical materials used in these processes:
- Tool Steels:
- D2: Known for its high wear and abrasion resistance, D2 is a high-carbon, high-chromium tool steel. It’s commonly used in long-run stamping operations due to its ability to retain a sharp cutting edge. However, it can be brittle and may not be the best choice for materials that produce a lot of shock or impact.
- A2: A versatile air-hardened tool steel with good toughness and stability during heat treatment. A2 strikes a balance between wear resistance and toughness. It can withstand non-repetitive loads that would typically crack other high-carbon steels.
- O1: An oil-hardened tool steel that offers excellent wear resistance and is relatively easy to machine. It is a common choice for small to medium-size production runs where intricate tool shapes are required.
- Carbide:
- Tungsten Carbide: Extremely hard and wear-resistant, this material is used for high-volume production due to its ability to maintain a sharp edge over extended periods. Tungsten carbide molds are often more expensive than tool steel, but their longevity in production can justify the cost.
- High-Speed Steel (HSS):
- M2: A general-purpose HSS with a good combination of toughness, wear resistance, and red hardness, which makes it suitable for cutting tools like taps, drill bits, and also stamping operations.
- M42: With a higher cobalt content, M42 is used for more demanding cutting tools that require higher red hardness and where very high cutting speeds are necessary. This makes it suitable for very challenging stamping jobs.
- Aluminum:
- 7075: While not as common for high-volume stamping molds, aluminum alloys like 7075 are sometimes used for low-volume runs or for forming softer materials. Aluminum is quick to machine and has excellent thermal conductivity, but it wears out much faster than tool steel or carbide.
Comparison among these materials:
- Tool Steels (D2, A2, O1) are excellent for varied volumes of stamping operations, offering a balance between cost, wear resistance, and ease of maintenance. These various grades allow for choosing the best material based on the specific need for toughness or wear resistance.
- Tungsten Carbide is best for high-volume and precision stamping as it maintains its edge longer, but the initial cost is substantially higher and the material is more brittle.
- High-Speed Steels (HSS) (M2, M42) are ideal for high-speed, high-temperature operations. They hold their hardness at higher temperatures, which allows for faster stamping without losing tool integrity.
- Aluminum (7075) is chosen for specific applications where quick turnaround, low volumes, or a gentle touch on the stamped material is required. It is less durable and typically not suitable for general stamping of hard materials or high-volume runs.
Selecting the appropriate material for a stamping or punching mold depends on the project’s needs, including the material to be stamped, production volume, and the desired lifespan of the mold.
