P20 and 718H are two of the most widely used pre-hardened plastic mold steels in the injection molding industry. They are both cost-effective and easy to process, and are known as the “golden partners” of plastic injection molds. However, there are obvious differences in their performance and application scenarios. Choosing the wrong one will not only increase production costs, but also affect the quality of plastic products. This article will compare P20 and 718H in detail to help you choose the most suitable mold steel for your injection molds.

Core Differences Between P20 and 718H

P20 and 718H are both pre-hardened plastic mold steels, but there are significant differences in chemical composition, hardness, polishability and other aspects:

1. Chemical Composition & Hardness

The chemical composition of 718H is based on P20, with added nickel (Ni) and other elements, which makes its performance better than P20. The specific comparison is as follows:

2. Application Scenarios for Injection Molds

The biggest difference between P20 and 718H lies in their application scenarios. You can choose according to the precision, surface quality and production batch of your plastic products:

P20 Mold Steel Application Scenarios

P20 is suitable for ordinary plastic injection molds with low requirements on product surface quality and precision, such as:

• Ordinary plastic products (such as plastic buckets, plastic chairs, daily necessities)
• Small-batch injection molds (production batch less than 100,000 pieces)
• Injection molds for low-precision plastic parts (such as plastic brackets, shell accessories)

P20 is cost-effective and easy to process, which is the first choice for small and medium-sized enterprises to produce ordinary plastic products. For example, many manufacturers use P20 mold steel to produce plastic buckets and plastic chairs, which can meet the basic production needs and control costs.

718H Mold Steel Application Scenarios

718H is suitable for high-precision, high-gloss plastic injection molds, such as:

• High-precision plastic products (such as automotive interior parts, electronic product shells)
• Large-batch injection molds (production batch more than 100,000 pieces)
• Injection molds for high-gloss plastic parts (such as cosmetic packaging, medical device shells)

718H has better polishability and toughness than P20, which can ensure the surface quality and precision of plastic products, and is suitable for large-batch production. For example, automotive interior parts (such as dashboard, door panel) require high precision and surface gloss, so 718H mold steel is usually used to make injection molds.

Processing Difficulty & Cost Comparison

• Processing Difficulty: Both P20 and 718H are pre-hardened steels, which can be directly processed without heat treatment. P20 is easier to process due to its lower hardness, while 718H has higher hardness and slightly higher processing difficulty, but it can still be processed with ordinary equipment.
• Cost: The price of 718H is about 20-30% higher than that of P20. This is because 718H adds nickel and other elements, and its production process is more complex. For small-batch, low-precision production, P20 is more cost-effective; for large-batch, high-precision production, 718H can reduce mold replacement frequency and is more cost-effective in the long run.

Purchasing Suggestions

To help you make a quick decision, here are simple purchasing suggestions:

1. If you produce ordinary plastic products, small batch, low precision → Choose P20 (cost-effective, easy to process).
2. If you produce high-precision, high-gloss plastic products, large batch → Choose 718H (good performance, long mold life).
3. If you are unsure about the selection, you can provide us with your product requirements (precision, surface quality, production batch), and we will give you free selection advice.

We provide high-quality P20 mold steel and 718H mold steel, all of which are pre-hardened and can be directly processed. We also provide custom cutting, milling and grinding services to meet your different mold size requirements. Contact us now to get a free quote and material data sheet!