MOLD TOOLING GUIDE · STEEL SELECTION
Quick answer: P20 is a practical general-purpose option, H13 is suited to demanding thermal and wear conditions, and S136 is often selected when corrosion resistance, polishing, or clean surfaces matter. The final choice should match the resin, finish, volume, tool life, and maintenance plan.
Choosing injection mold steel affects tooling cost, polishing quality, wear resistance, corrosion resistance, and expected mold life. P20, H13, and S136 are common choices, but the best option depends on the resin, surface finish, production volume, and part requirements.
P20 Mold Steel
P20 is a practical pre-hardened steel for many general-purpose injection molds. It offers a useful balance of machinability, strength, cost, and mold life for standard production parts.
H13 Mold Steel
H13 is a hot-work tool steel known for toughness and resistance to thermal fatigue. It can be a strong choice for demanding applications, abrasive materials, or tooling that will experience repeated thermal cycling.
S136 Mold Steel
S136 is a corrosion-resistant stainless mold steel often considered for clear parts, high-polish surfaces, medical applications, and resins or environments where corrosion control matters.
How to Select Mold Steel
- Match the steel to the resin and any glass-fiber or mineral filler.
- Specify the required surface finish, polish, texture, or optical area.
- Consider annual volume, expected tool life, maintenance, and replacement risk.
- Confirm heat treatment, hardness, corrosion protection, and inspection documentation.
- Ask for the steel grade and certificate to be recorded in the tooling documentation.
Compare Tooling Options with an Engineer
Steel selection should be made together with the mold design, resin, surface finish, and production plan. Send your tooling requirements to Daremotion for an engineering review and quotation.
RFQ Checklist for Mold Steel
| Requirement | What to specify |
|---|---|
| Resin | Grade, glass fiber, mineral filler, flame requirement |
| Surface | Polish, texture, transparent or cosmetic area |
| Tool life | Prototype, annual volume, lifetime volume |
| Documentation | Steel grade, hardness, treatment, certificate |
FAQ
Is S136 always the best mold steel?
No. It is valuable for corrosion control and polished surfaces, but the correct choice depends on resin, volume, and tooling expectations.
When should H13 be considered?
Discuss H13 when thermal cycling, toughness, wear, or demanding resin conditions exceed a standard general-purpose tool.
Discuss Your Mold Steel Requirements
Send your tooling requirements to Daremotion for engineering review.