Understanding Rapid Prototyping Technology for CNC Punching Dies

High-strength and ultra-high-strength steels used in CNC stamping dies have enabled vehicle weight reduction while enhancing crashworthiness and safety, making them a key direction for steel development in the automotive industry. However, as strength increases, conventional cold stamping processes tend to induce cracking during forming, rendering them inadequate for processing high-strength steel sheets. In response to these limitations, the international community has increasingly focused on developing hot stamping technology for ultra-high-strength steel sheets. This innovative process integrates forming, heat transfer, and microstructural transformation into a single operation. It leverages the enhanced ductility and reduced yield strength of sheet metal in the high-temperature austenitic state to achieve desired part geometries through die-based forming.

In the past, when producing deep-drawn or heavily drawn workpieces with CNC punching dies, it was widely believed that pressure-resistant lubricating oils were the best choice for die protection. Sulfur- and chlorine-based extreme-pressure additives were long added to pure oils to extend die life. However, with the emergence of high-strength steels and increasingly stringent environmental regulations, the value of EP oil-based lubricants has declined, and they have even lost their market share.

When high-strength steel is formed at elevated temperatures, EP oil-based lubricants lose their performance and can no longer provide the physical die‑protective barrier required in extreme‑temperature applications. In such cases, IRMCO high‑solid polymer lubricants for extreme temperatures deliver the necessary protection. As the metal deforms within the stamping die, the temperature continuously rises; under these conditions, EP oil‑based lubricants thin out and, in some instances, may reach their flash point or even ignite. By contrast, when IRMCO polymer lubricants are applied by spraying, their consistency is typically much lower. As the forming temperature increases, the lubricant thickens and becomes more resilient. In fact, these high‑polymer, extreme‑temperature lubricants exhibit “heat‑seeking” behavior: they adhere to the metal surface, forming a friction‑reducing barrier. This protective layer enables workpieces subjected to demanding forming requirements to stretch without cracking or sticking, while effectively controlling friction and metal flow. As a result, the die is efficiently protected, its service life is extended, and stamping strength is improved.

Rapid Prototyping Technology for CNC Punching Dies

With the rapid economic development and the increasing diversification of market demand, there is a growing need for shorter product production cycles, particularly for small-batch and even single-piece production. This calls for modern manufacturing technologies that not only offer high flexibility but also enable faster, more agile production methods that can swiftly adapt to market requirements. Rapid prototyping technology for CNC stamping dies has emerged precisely to meet these demands.

In-mold tapping for CNC punching dies, also known as in-mold tapping, is a new technology that replaces traditional manual tapping. Conventional tapping equipment fails to meet the demands of stamped parts due to its low efficiency and long processing times, falling far short of market requirements. With the introduction of in-mold tapping technology, stamping dies have truly achieved automation and high efficiency. The tapping range spans from as small as M0.6 to as large as M45, with dimensional accuracy reaching 0.01 mm. This technology eliminates the need for secondary manual tapping after stamping, ensures consistent part quality, delivers excellent surface finish, boosts productivity, and reduces costs, making it widely adopted in the stamping industry.