Avoiding Common Mistakes When Selecting Steel for Injection Molds

Choosing the right steel grade for injection molds isn’t just about hardness—it’s about balancing performance, cost, lifespan, and plastic material compatibility. At Dongxinda Mould Technology Co., Ltd., we often help clients correct early-stage misjudgments in mold steel selection that could lead to costly maintenance or tool failure down the line.

Common Mistakes in Mold Steel Selection:

1. Over-Specifying for Low-Volume Projects
   Using hardened H13 steel for a mold expected to run under 100,000 shots increases cost with little benefit. For such projects, pre-hardened P20 or aluminum may suffice.

2. Under-Specifying for Abrasive Plastics
   Glass fiber–filled or flame-retardant materials require high-wear-resistant steel. Using basic P20 here can result in premature surface damage or part tolerance issues.

3. Ignoring Corrosion Conditions
   Molding in humid environments or with PVC or halogenated plastics? Stainless steel (like S136 or 420) is a better choice to prevent rusting and pitting.

4. Overlooking Polishability or Texture Requirements
   For high-gloss parts or fine textures, steel purity matters. Lower-grade steels may fail to achieve required finish.

How Dongxinda Helps Clients Choose Smartly:

• Technical consultation during quotation

• Material comparison tables (life span, machinability, polishability)

• Integrated surface treatment options: nitriding, PVD, hard chrome

FAQs:

• Can I change steel type after quoting?
  Yes, as long as machining hasn’t started. We’ll re-quote based on the new material.

• What’s the best steel for mirror-finished molds?
  S136, 420SS, or other high-purity stainless steel grades with fine grain structure.

• Do you offer heat treatment certification?
  Yes. We provide certificates for hardness and steel origin upon request.