What is Special Molds and when should I choose it?

Special molds cover custom tooling that does not fit a standard category, such as complex multi-material or unusual-geometry parts. Choose them when your project needs a tailored tooling approach.

What materials can be used for Special Molds?

A range of materials is available, including P20 / 718 Pre-Hardened Steel, H13 Hardened Steel, S136 Stainless Mold Steel, NAK80 Mold Steel, Aluminum Tooling. The best choice depends on strength, appearance, operating environment, and budget. Our engineers can help you select the right one during the quote review.

What tolerances can Special Molds achieve?

Achievable tolerances depend on material, part size, and geometry. Typical values are listed on this page, and tighter tolerances can often be held on critical features. Share your drawing and we will confirm during the DFM review.

Can you support both prototype and production Special Molds?

Yes. We support everything from a single prototype to ongoing production programs, so you can scale without changing supplier.

How much does Special Molds cost?

Cost depends on material, part size and complexity, quantity, tolerances, and finishing. Upload your CAD model and drawing to receive a quote, and our engineers can suggest design changes that reduce cost.

What file formats do you accept for Special Molds quotes?

We accept common 3D CAD and 2D drawing formats, including STEP, STP, IGES, STL, SLDPRT, X_T, DXF, DWG, and PDF. If your format is not listed, please contact us.

How quickly can you deliver Special Molds parts worldwide?

Lead time depends on process, quantity, and finishing. Prototypes can often ship within a few business days, and we ship worldwide. Contact us with your requirements for a lead-time estimate.

What kinds of projects fall under special molds?

Projects with unusual geometry, multi-material requirements, or special performance needs that go beyond standard mold designs.

Special Molds – Mastars

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Injection Molding

Plastic Tooling

Special Molds

800⁺

Global Customers Served

100⁺

Total Equipments

5⁺

Production Bases

100⁺

Engineering & Design Veterans

18⁺

Manufacturing experience of years

20⁺

Technical patents

Our Special Molds Capabilities

Complex Geometry

Side actions, lifters, and unusual mold structures.

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Multi-Material Tooling

Molds for two-shot and other multi-material parts.

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Custom Requirements

Tooling shaped around your specific needs.

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Engineering Support

Early collaboration on moldability and tooling design.

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Tailored Tooling Solutions

If your part is unusual, talk to our engineers early. We will recommend a tooling approach that fits.

Talk to Our Engineering Team

Plastic Tooling Materials

Choose from a range of materials for prototyping and production. Our engineers can help you select the best option for strength, appearance, environment, and budget.

P20 / 718 Pre-Hardened Steel

H13 Hardened Steel

S136 Stainless Mold Steel

NAK80 Mold Steel

Aluminum Tooling

P20 / 718 Pre-Hardened Steel

Pre-hardened tool steel is a common choice for medium-volume molds because it machines well and needs no further hardening.

Key Characteristics

Good machinability

No heat treatment needed after machining

Good polishability for general parts

Common Grades: P20, 718, 718H

Typical Applications: Medium-volume molds for general plastics

Available Finishes: Texturing, polishing

H13 Hardened Steel

H13 is a hot-work tool steel offering high hardness and thermal fatigue resistance for long-life production molds.

Key Characteristics

High hardness and wear resistance

Good thermal fatigue resistance

Suitable for high-volume molds

Common Grades: H13, 1.2344

Typical Applications: High-volume molds, glass-filled materials

Available Finishes: Polishing, nitriding

S136 Stainless Mold Steel

S136 is a corrosion-resistant stainless mold steel with excellent polish, used for optical and medical parts.

Key Characteristics

Excellent polishability

Good corrosion resistance

Suitable for clear and PVC parts

Common Grades: S136, 420 stainless

Typical Applications: Optical, medical, and corrosive-resin molds

Available Finishes: Mirror polishing

NAK80 Mold Steel

NAK80 is a pre-hardened steel with fine, uniform structure that polishes well and holds texture detail.

Key Characteristics

Fine uniform structure

Very good mirror finish

Good for photo-etched texture

Common Grades: NAK80

Typical Applications: High-gloss and textured cosmetic parts

Available Finishes: Mirror polishing, texturing

Aluminum Tooling

Aluminum molds are machined quickly and cost less, making them suitable for prototype tooling and low-volume runs.

Key Characteristics

Fast machining and short lead time

Lower tooling cost

Good heat transfer

Common Grades: 7075, 6061

Typical Applications: Prototype tools, bridge tooling, low-volume production

Available Finishes: Machined or lightly polished

Surface Finishing Options

Enhance appearance, corrosion resistance, and durability with finishing options matched to your material and application.

Finishing Option	Typical Effect	Suitable Materials	Typical Use
Machined Finish	Standard machined cavity surface.	All mold steels	Hidden or functional surfaces
Polishing	Smooth to mirror finish according to SPI grade.	S136, NAK80, H13	Clear and high-gloss parts
Texturing (Etching)	Grained or patterned surface on molded parts.	P20, NAK80, H13	Automotive trim, housings, handles
Nitriding / Coating	Increased surface hardness and wear resistance.	H13, P20	Glass-filled materials, long runs

Special Molds Tolerances & Lead Times

Typical capabilities for prototype and production parts. Contact our engineering team for requirements beyond the values below.

Capability	Typical Value
Mold Types	Single, multi-cavity, and family molds
Typical Mold Life	Depends on steel and material; confirmed during mold design
Tooling Lead Time	Confirmed after DFM review and mold design
Order Quantity	From prototype tools to high-volume production molds

* Mold life, cavity count, and lead time depend on part design and target volume, and are confirmed during mold design review.

Special Molds Equipment & Manufacturing Capabilities

CNC Mold Machining

EDM & Wire-Cut Machines

Mold Trial & Inspection

Special Molds Project Showcase

Why Choose Mastars for Special Molds?

In-House Mold Design & Making

Mold design, machining, polishing, and trial under one roof for faster delivery and clear accountability.

100+ Engineering Professionals

Direct access to engineers for DFM, mold flow review, and tooling strategy.

Certified Quality Systems

ISO 9001, ISO 13485, and IATF 16949 certified processes supported by documented inspection procedures.

Prototype to Production Tooling

Aluminum prototype tools to hardened steel production molds, matched to your volume.

DFM Review on Every Order

Feedback on draft, parting lines, gating, and cooling before mold design is released.

Trusted by Global Engineering Teams

Supporting customers across medical, automotive, electronics, packaging, and consumer products.

Certifications

ISO9001:2015 Certificate

IATF16949:2016 Certificate

ISO13485:2016 Certificate

Medical A-Class Supplier

Partners

How Special Molds Works

Upload Your Design

Share your CAD files, drawings, quantity, material, and any critical requirements.

Get an Engineer-Reviewed Quote

Receive pricing, lead time, and manufacturability feedback based on your part requirements.

Production Begins

Once you approve your quote, manufacturing starts — from prototype tooling to full-scale runs.

Parts Shipped

Finished parts are inspected, packaged, and shipped with the required quality documentation.

Get a Quote

What Our Customers Say

Charlie Ozana

Company: 445 LTDJob Title: CEOBusiness: Full turnkey company

Mastars in all my projects are partners. So I get all the support that I need from engineering management, pricing, timetable, QA, everything is as a partner, not as a supplier. For me, Masters is like home.

Nathan Johnson

Company: Gusto Global IndustriesJob Title: DirectorBusiness: Dust reduction system

They were such a lovely company to deal with, and we couldn't be more happier even to today down the track with even more products moving forward. Very professional, easy to deal with, get back to you straight away, contact is easy through WeChat and email, move forward as quickly as you can.

Oded Kalawanl

Company: Annabella Tech IsraelJob Title: R&D managerBusiness: Breast pump

We managed to make it in a very short time warm prototyping to mass production and FDA approval. That makes me feel confidence to choose Mastars.

Jade Harris

Company: Buddy SystemJob Title: Co-founderBusiness: Wireless instant safety alert device

We're glad that we found a company like Mastars to make the product for us because it's been so good to deal with. They're a really good company.

Dror Harel

Company: BlonessJob Title: General ManagerBusiness: L300, H200

I think the relationship between the buyers and definitely between me the Mastars it's like a family relationship and this is why we are so happy to produce in Mastars and this is why we came for 15 years. By the way, now we came with a new product that we come to Master to produce for the new year.

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Special Molds Service FAQs

What is Special Molds and when should I choose it?

Special molds cover custom tooling that does not fit a standard category, such as complex multi-material or unusual-geometry parts. Choose them when your project needs a tailored tooling approach.
What materials can be used for Special Molds?

A range of materials is available, including P20 / 718 Pre-Hardened Steel, H13 Hardened Steel, S136 Stainless Mold Steel, NAK80 Mold Steel, Aluminum Tooling. The best choice depends on strength, appearance, operating environment, and budget. Our engineers can help you select the right one during the quote review.
What tolerances can Special Molds achieve?

Achievable tolerances depend on material, part size, and geometry. Typical values are listed on this page, and tighter tolerances can often be held on critical features. Share your drawing and we will confirm during the DFM review.
Can you support both prototype and production Special Molds?

Yes. We support everything from a single prototype to ongoing production programs, so you can scale without changing supplier.
How much does Special Molds cost?

Cost depends on material, part size and complexity, quantity, tolerances, and finishing. Upload your CAD model and drawing to receive a quote, and our engineers can suggest design changes that reduce cost.
What file formats do you accept for Special Molds quotes?

We accept common 3D CAD and 2D drawing formats, including STEP, STP, IGES, STL, SLDPRT, X_T, DXF, DWG, and PDF. If your format is not listed, please contact us.
How quickly can you deliver Special Molds parts worldwide?

Lead time depends on process, quantity, and finishing. Prototypes can often ship within a few business days, and we ship worldwide. Contact us with your requirements for a lead-time estimate.
What kinds of projects fall under special molds?

Projects with unusual geometry, multi-material requirements, or special performance needs that go beyond standard mold designs.