What mold steel do you use for silicone molds?

We machine molds in P20, NAK80 and S136 steel. P20 is a cost-effective pre-hardened steel for short-to-medium runs; NAK80 delivers a high-polish, transparent-part finish; S136 is a stainless steel for medical and food-contact tools. Hardened H13 is available for very high-volume runs.

What tolerance can CYES hold on a mold cavity?

We machine mold cavities to ±0.01 mm on critical dimensions using CNC and EDM. Finished silicone part dimensions typically hold ±0.1–0.3 mm depending on part size, because silicone is flexible — the tolerance plan is confirmed during DFM review.

How long does it take to make a silicone mold?

A single-cavity prototype mold typically takes 7–15 days, and a multi-cavity production mold 15–30 days, depending on part complexity and cavity count. We confirm the schedule after DFM review.

Do you provide lifetime mold maintenance?

Yes. Molds built by CYES include lifetime maintenance and repair under one roof, so your tooling stays accurate and productive across the entire product life.

In-House Silicone Mold Making

CNC machining, EDM and precision steel tooling under one roof — building silicone molds that hold ±0.01 mm cavity tolerance and last for the life of your product.

Precision Tooling

From Mold Steel to Finished Cavity

Every silicone product starts with a precision mold. Our in-house tooling workshop machines mold cavities from P20, NAK80 and S136 steel using CNC and EDM, then finishes, polishes and validates each cavity before it reaches the press.

CNC machining — high-precision mold cavities to ±0.01 mm
EDM — fine details, sharp features and mirror finish
P20 / NAK80 / S136 steel — matched to your run size and finish
Lifetime maintenance — repair and upkeep under one roof

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CNC machining center milling a precision silicone mold cavity at the CYES tooling workshop

Inside Our Tooling Workshop

Real Mold Making, Real Equipment

Photographs from our in-house tooling workshop — the machines and mold steel behind every CYES silicone part.

CNC milling sparks while machining a silicone mold cavity

CNC Cavity Machining

High-speed CNC milling cuts mold cavities and cooling channels to ±0.01 mm before EDM finishing.

Polished S136 stainless mold steel block in the CYES tooling workshop

Premium Mold Steel

S136 stainless, NAK80 high-polish and P20 pre-hardened steel — selected for finish, run size and compliance.

Mold plates with guide pins, cavities and cooling channels on the CYES workbench

Mold Assembly

Guide pins, cavities, venting and cooling channels assembled and validated before first-shot trial.

Organized mold storage racks with steel molds at CYES

Organized Tooling Library

Every customer mold is catalogued and stored, so reorders and revisions stay fast and consistent.

Engineer designing a silicone mold cavity in CAD at CYES

CAD-Driven Design

Mold geometry is designed in CAD with DFM review, draft analysis and shrinkage compensation built in.

Open silicone mold showing molded clear parts at CYES

First-Shot Validation

Molds are trialed and samples measured before they are released to production.

Tooling Specifications

Mold Specifications

Standard tooling capability at CYES. Each parameter is confirmed for your specific part during DFM review.

Parameter	Capability
Mold cavity tolerance	±0.01 mm on critical dimensions (cold-runner LSR tooling to ±0.005 mm)
Mold steel	P20, NAK80, S136 (hardened H13 for high volume)
Polishing	SPI A1–A2 mirror to textured finishes
Cavity count	Single-cavity to 64-cavity tooling
Prototype lead time	7–15 days (single cavity)
Production mold lead time	15–30 days (multi-cavity)
Maintenance	Lifetime repair and upkeep included

Steel Selection

Choosing the Right Steel

P20

Pre-hardened tool steel — the cost-effective default for short-to-medium production runs.

NAK80

High-polish steel for transparent or glossy parts that need a flawless, mirror-like surface.

S136

Stainless tool steel for medical, food-contact and high-purity applications requiring corrosion resistance.

H13 (hardened)

Hardened steel for very high-volume runs and abrasive silicone compounds.

Ready to Start Your Mold?

Send your drawing or sample — we'll return a DFM review and mold quotation within 24 hours.

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