Plastic Mold Steel Comparison: P-20 vs. XPM vs. NAK80 vs. SKD61

Mold Steel Stock – P20, XPM,NAK80,SKD61 and Tool Steel Blocks for Injection Mold Manufacturing

Introduction

The selection of steel for plastic injection molds has a direct impact on mold lifespan, product quality, and manufacturing cost. In the design and production of automotive lighting molds, multi-color molds, and high-precision tooling, different types of steel vary in terms of properties, heat treatment compatibility, and price. This article provides an in-depth analysis of commonly used mold steels in the industry—P-20, XPM, NAK80, and SKD61—to help you quickly understand their characteristics, suitable applications, and make the best choice based on your technical requirements and budget.

Performance Analysis of Common Plastic Mold Steels

1. P-20

• Features: Excellent machinability and polishability, stable dimensional accuracy, and suitable for high-volume production requirements.

• Applications: General plastic injection molds, automotive components, and electronic product housings.

• Material Hardness: HRC 28–32 (pre-hardened)

• Heat Treatment Limitations: Typically used with surface treatments such as nitriding or chrome plating; not suitable for further deep heat treatment.

• Advantages: Cost-effective and excellent machinability.

• Disadvantages: Limited corrosion resistance and not suitable for applications requiring high hardness.

• Price Reference: Economical grade (approximately NT$50–60 per kg)

2. XPM

• Features: Uniform pre-hardened structure, excellent dimensional stability, with superior strength and toughness compared to P-20.

• Applications: Large plastic molds, multi-cavity molds, and automotive plastic components.

• Material Hardness: HRC 38–42 (pre-hardened)

• Heat Treatment Limitations: Typically not subjected to further heat treatment; used at its original pre-hardened condition.

• Advantages: High dimensional accuracy; ideal for complex structures and multi-cavity molds.

• Disadvantages: Slightly more expensive than P-20.

• Price Reference: Mid-range (approximately NT$70–90 per kg)

  
  

3. SKD61

• Features: Excellent heat resistance and wear resistance; ideal for high-temperature and special application products.

• Applications: Engineering plastic molds, high-temperature injection molds, and molds for special heat-resistant components.

• Material Hardness: Pre-hardened HRC 40–52。

• Heat Treatment Capability: Can undergo deep heat treatment to achieve very high hardness, up to HRC 48–52.

• Advantages: Suitable for high-temperature environments, excellent wear resistance, and extremely long service life.

• Disadvantages: Difficult to machine and relatively high in cost.

• Price Reference: Mid-to-high price range (approximately NT$170–220 per kg)

  
  

4.NAK80

• Features: Excellent polishability and machinability; ideal for products requiring high gloss and mirror-finish surfaces.

• Applications: Optical component molds, transparent plastic parts, cosmetic packaging, and consumer electronics housings.

• Material Hardness: HRC 38–42 (pre-hardened)

• Heat Treatment Limitations: Further heat treatment is not recommended; machining is performed at the original pre-hardened condition.

• Advantages: Capable of achieving high-quality mirror finishes without additional treatment; excellent dimensional stability.

• Disadvantages: Moderate corrosion resistance and high cost.

• Price Reference: High price range (approximately NT$300–350 per kg)

  
  

Mold Steel Saw Cutting with Coolant

How to Choose the Right Mold Steel for Your Application?

鋼材	Price Level	Recommended Applications
P-20	Economical	General plastic molds, high-volume production
XPM	Mid-range	Large multi-cavity molds, automotive parts
SKD61	Mid-to-high	High-temperature, engineering plastic, and wear-resistant molds
NAK80	High-end	High-gloss and mirror-finish plastic products

For automotive lighting molds and multi-color injection mold designs, NAK80 or XPM is typically selected to meet high standards of surface finish and dimensional accuracy. If the product requires long-term heat resistance and wear durability, SKD61 is recommended. For general-purpose molds or cost-sensitive high-volume production, P-20 offers the best balance of performance and value.

HOWMIN's Professional Mold Solutions

HOWMIN specializes in the design and manufacturing of plastic injection molds, offering advanced 5-axis machining and deep-hole drilling capabilities. We precisely recommend suitable mold steel based on each client’s requirements. Whether for automotive lighting molds, multi-color injection molds, or high-precision plastic parts, we help our clients achieve the optimal balance between quality and cost.

If you have any questions regarding mold steel selection or mold design and manufacturing, feel free to contact our team — we are ready to provide the most professional and tailored advice for your needs!

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