Mold Steel Secrets: Matching Material to Mold for Longevity
Introduction
Choosing the right mold steel is critical to withstand wear, corrosion, and thermal stress. The product’s material (e.g., PP, ABS, POM, or glass-filled nylon) dictates steel grade selection.
Material-Specific Guidelines
Commodity Plastics (PP, PE, ABS)
Steel Choice: P20 or 718H (pre-hardened steel).
Why: Cost-effective for low-to-mid volumes; resists abrasion from additives.
Engineering Plastics (PC, Nylon, POM)
Steel Choice: H13 (hot-work steel) or S136 (stainless).
Why: High thermal stability for precise molding; resists corrosion from moisture-sensitive resins.
Abrasive/Filled Materials (GF-Nylon, Mineral-Filled PP)
Steel Choice: Hardened steels like DIN 1.2344 (ESR) or powder-metallurgy steels.
Why: Superior wear resistance; extends mold life despite glass fibers.
Corrosive Materials (PVC, Flame-Retardant ABS)
Steel Choice: Stainless steel (e.g., 420SS) or nickel-plated steels.
Why: Prevents pitting and degradation from acidic byproducts.
Pro Tip:
For high-gloss finishes (e.g., consumer electronics), use polished steels like NAK80 or S136 with mirror finishes.
Case Study
A medical device manufacturer switched from P20 to H13 for PEEK molding, achieving 500k cycles without significant wear.
Conclusion
Balance cost, volume, and material properties. Invest in higher-grade steels for aggressive materials to avoid frequent mold repairs.
