Steels for Plastic Models
Steels for plastic modeling; Selecting the right steel for plastic injection molds is not just a technical decision: it's a strategic investment that directly impacts final product quality, operational efficiency, and process profitability. In the molding industry, where every millisecond counts, choosing a steel with balanced metallurgical properties can make the difference between a reliable mold and one that fails prematurely.
Today we present three steels that have proven their worth in demanding applications: 420 Mod. (DIN 1.2083), DIN 1.2085 y P20 + Ni (DIN 1.2738)All designed to meet the highest performance standards in plastic injection molds.
Steel for Plastic Model 420 Mod. (DIN 1.2083)
The steel 420 Mod. It is an evolution of the classic AISI 420, with a martensitic formulation that allows it to offer high hardness after quenching and tempering. Its main strength lies in its excellent resistance to corrosion and oxidation, making it the ideal choice for molds exposed to corrosive plastics such as PVC or in environments where moisture and chemical additives are common 420 Mod.
Among its most notable attributes:
- Hardness up to 50 HRC.
- High polishing capacity, ideal for molds with aesthetic or optical requirements.
- Good dimensional stability after heat treatment.
- Tensile strength up to 1,780 N/mm².
It is widely used in molds for the medical industry and can replace conventional stainless steels such as 304 or 316L, providing greater wear resistance without losing the anti-corrosion advantage420 Mod.
Steel for Plastic Model DIN 1.2085
When it comes to protecting your investment in large molds or long-term storage, DIN 1.2085 is the best choice. This pre-hardened maraging steel was developed for cavity holders and mold holders, with superior corrosion resistance thanks to its high chromium content (16%) and pre-hardened state.
Key benefits of DIN 1.2085 plastic model steels:
- Hardness between 31 and 36 HRC from the factory, ready to use.
- Excellent machinability due to its sulfur and manganese content.
- Optimized thermal conductivity (17 W/m°C), ideal for controlled injection cycles.
- Perfect for environments where steel may be exposed to the elements or stored for long periods.
This steel can replace machine grade steels such as 4140T or 4340T, and is particularly useful in molds that require structural strength and corrosion protection
Steel for Plastic model P20 + Ni (DIN 1.2738)
The steel P20 + Ni represents the ideal solution for molds with high requirements for surface finish and durabilityThanks to the addition of nickel, this material offers superior hardenability, achieving uniform hardness even in large-volume parts. Furthermore, its structure allows for processes such as photoetching and nitriding, extending its useful life and functional performance.
Competitive advantages of P20 plastic model steels:
- Uniform hardness between 28 and 34 HRC, even in large sections.
- Excellent polishing ability.
- Good performance in CNC machining processes.
- Possibility of surface hardening to more than 50 HRC via nitriding or flame.
P20 + Ni is highly valued in applications requiring precision and aesthetics, such as molds for electronic housings or mirror-finished parts. It is also suitable for die components and mechanical parts such as shafts and crankshafts.
Three steels for plastic models, one goal
Each of these steels responds to different challenges in plastic molding. While 420 Mod. Noted for its chemical resistance and optical finish, the DIN 1.2085 excels as a corrosion-resistant mold carrier, and the P20 + Ni It offers an ideal balance between hardness, machinability and highly aesthetic finishes.
In a market that demands greater efficiency, durability and precision, investing in specialized steels is not just a technical decision, it is a smart competitive strategy.
Want to choose the right steel for your next molding project? Contact us en Serviacero Especiales and let our team advise you.
Optimize your process, extend the life of your molds, and guarantee the quality of each injection.
