Views: 0 Author: Site Editor Publish Time: 2026-05-25 Origin: Site
Many customers ask questions like:
“What steel do you use for the mold?”
“What is the difference between P20 and H13?”
“Why do mold prices vary so much?”
In fact, mold steel directly affects mold lifespan, product quality, production efficiency, and long-term maintenance costs.
Different products, plastic materials, and production volumes require different mold steels.
Some molds are designed for only a few thousand cycles, while others must run reliably for millions of shots. That is why choosing the right mold steel is so important.
Below are some of the most commonly used steels in the plastic injection mold industry.
P20 is one of the most widely used steels in plastic injection molds.
It is a pre-hardened mold steel that offers a good balance between cost, machinability, and durability.
P20 is widely used for:
Plastic chair molds
Household product molds
Paint bucket molds
Storage box molds
Daily-use plastic products
Easy to machine
Reasonable cost
No additional heat treatment required
Stable mold performance
For standard plastics such as PP, PE, and ABS, P20 is suitable for most production needs.
Many medium-volume molds are built with P20 steel.
If the plastic contains glass fiber or the customer requires a very long mold life, H13 is usually a better option.
H13 is a hot-work tool steel with better wear resistance and heat resistance than P20.
Automotive molds
Engineering plastic molds
PA+GF molds
High-temperature plastic products
High hardness
Excellent wear resistance
Long mold lifespan
Suitable for high-volume production
Of course, H13 is more expensive and more difficult to machine.
Many automotive industry molds specify H13 steel.
Some products require an excellent surface finish, such as:
Cosmetic packaging
Medical products
Transparent plastic parts
Optical products
In these cases, S136 or 420 stainless steel is often the preferred choice.
The biggest advantages of this steel are:
Corrosion resistance
Excellent polishing performance
Mirror-finish capability
Stainless mold steel is especially suitable for corrosive plastics such as PVC.
Many mold manufacturers consider 718 steel an upgraded version of P20.
Compared with standard P20, it offers better hardness, wear resistance, and surface quality.
718 steel is widely used in office chair molds and large furniture molds.
Longer mold life than P20
Better surface finish
Suitable for medium-to-high-end products
718 is also a popular choice for export molds.
45# steel is commonly used in Chinese mold factories.
Although it is not considered a professional tool steel, its low cost and easy machining make it a practical choice for budget-friendly molds.
It is often used for:
Mold bases
Support plates
Low-volume molds
Structural mold components
For products with smaller production quantities, 45# steel can still be a cost-effective solution.
One of the biggest concerns for customers is mold lifespan.
Below is a general industry reference:
Mold Steel | Typical Mold Life |
|---|---|
45# Steel | 50,000 – 200,000 shots |
P20 Steel | 300,000 – 500,000 shots |
718 Steel | 500,000 – 800,000 shots |
H13 Steel | 1,000,000+ shots |
S136 Steel | 1,000,000+ shots |
Actual mold life also depends on:
Product structure
Plastic material
Glass fiber content
Mold maintenance
Injection molding process
Even with the same steel, mold lifespan can vary greatly depending on the application.
Not necessarily.
The most important thing is choosing the right steel for the project.
For example:
If the product is made from standard PP material and the expected production volume is only a few hundred thousand shots, using H13 may unnecessarily increase mold cost.
However, for PA+GF materials or long-term mass production, higher-grade steel may actually reduce long-term costs.
A good mold solution is not the most expensive one — it is the most suitable one.
At HUAJI MOULD, we recommend mold steel based on:
Plastic material
Expected production volume
Surface finish requirements
Budget
Target market
For example:
Household products → P20
Office chair molds → 718 or H13
High-gloss products → S136
Glass-filled materials → H13
This helps customers balance cost, mold lifespan, and production stability.
Different products require different mold steel solutions.
If you are developing:
Plastic chair molds
Office chair molds
Household molds
Paint bucket molds
Motorcycle part molds
Feel free to contact HUAJI MOULD Official Website.
We can help you select the most suitable mold steel and mold solution according to your product and budget.
