Mold Building | Westec Plastics | Premier Medical Injection Molding and Custom Plastic Manufacturers in California

Precision Tooling for High-Performance Injection Molding

At Westec Plastics, every successful molding program begins with the same foundation: precision-built, properly maintained tooling. For more than 50 years, our in-house mold building team has combined advanced manufacturing technology, engineering expertise, and rigorous quality systems to deliver tooling that supports long-term performance, tight tolerances, and reliable, repeatable production.

From prototype cavities and production tools to ongoing maintenance and repair, we provide full lifecycle tooling support under one roof — reducing downtime, shortening lead times, and ensuring every mold meets the exact specifications required for medical, biotech, industrial, electronics, and consumer applications.

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Advanced Mold Building Technology, Backed by Engineering Expertise

Our mold building capabilities include everything required to support complex programs with high precision and tight performance requirements. With a fully equipped in-house tool room and a team of industry veterans, Westec offers:

CNC machining
EDM machining
Surface grinding and polishing

Laser engraving
Mold repair and refurbishing
Dimensional verification and tool steel selection guidance

Whether you need a single-cavity prototype insert or a multi-cavity production-ready mold, our experienced toolmakers ensure every tool is designed and built for manufacturability, accuracy, and longevity.

3D Printed Cavities and Cores with the Mantle P-200 Metal 3D Printer

Westec is one of the first molders to integrate the Mantle P-200 metal 3D printing system directly into a production tool room. This hybrid approach blends additive precision with traditional toolmaking, allowing us to:

Accelerate prototype and pre-production insert builds
Print P20 and H13 steel inserts with excellent dimensional accuracy
Cut lead times from 12+ weeks down to 2–4 weeks
Reduce cost by printing only the cavity/core, not a full tool
Improve design flexibility while maintaining tool steel durability

The Mantle P-200 allows us to complete up to 70% of the tool insert in-house, after which our toolmakers finish the critical surfaces and tolerances by hand — delivering a precise, production-ready mold far faster than conventional processes.

Explore our full 3D Printed Cavities and Cores capabilities →

Mold Building for Manufacturability

Effective mold design is critical to performance. Our team provides Design for Manufacturability (DFM) support early in the development cycle to ensure each tool is optimized for:

Resin flow and gate design
Cooling efficiency
Dimensional stability
Part geometry and draft
Cycle time optimization
Surface finish requirements

Quality Tooling: Built for Precision, Reliability, and Longevity

The quality of your molded part is only as strong as the quality of the tool behind it. Westec builds molds using commercial-grade steels such as P20, H13, and 420 stainless to maximize longevity, dimensional accuracy, and stability over long production runs. We never rely on low-grade or inconsistent tool steels, ensuring each mold delivers:

Tight tolerances
Predictable shrink and flow behavior
Long-term wear resistance
Stable cycle times
Repeatability across thousands or millions of cycles

Domestically built tooling also ensures faster communication and stronger oversight during the design and build phases.

Mold Maintenance, Repairs, and Modifications

Tool longevity depends on consistent, proactive care. Our in-house toolmakers offer:

Scheduled mold maintenance programs
Quick-turn repairs to minimize downtime
Insert replacements
Component rebuilds
Engineering changes and modifications
Flash or wear correction

By handling maintenance and repairs internally — rather than sending tools off-site — we dramatically reduce delays and help keep production schedules on track.

Plastic Fabrication and Value-Added Operations

To complement our mold building capabilities, Westec also provides a range of value-added fabrication and secondary services, including:

Ultrasonic welding
Pad printing
Vibration welding
Heat staking
Assembly
Cleanroom operations
In-house metrology

These services allow customers to consolidate vendors and maintain tighter control over quality, sterility, and final assembly requirements.

Full Lifecycle Tooling Support — From Prototype to Production

Whether you are developing a new medical device, scaling a biotech consumable, or transitioning a complex electronics enclosure from prototype to high-volume production, Westec delivers end-to-end tooling lifecycle support, including:

Prototype cavities and small launch tooling
Production tooling built for longevity
Mold transfers and refurbishment
Ongoing maintenance and repairs
Insert or cavity upgrades as programs evolve

With both additive and traditional tooling capabilities in-house, customers get fast turnaround, domestic quality, and long-term flexibility.

Get Started with Precision-Engineered Injection Mold Tools

High-quality parts start with high-quality tooling, and Westec is committed to delivering both. Whether you’re building a new tool, transferring an existing mold, or exploring advanced 3D printed cavities, our experienced team is ready to support your next program.

Let’s build your next mold — contact Westec today.

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