NAK80 is a premium pre-hardened plastic mold steel developed for high-gloss appearance molds, precision texture patterns and short-cycle mold production. As a nickel-aluminum precipitation hardening steel, NAK80 is delivered with a stable factory hardness of approximately 38-42 HRC, allowing mold manufacturers to directly perform CNC machining, EDM processing, polishing and texture etching without additional heat treatment.

Unlike conventional pre-hardened steels such as 718H, NAK80 is specially optimized for mirror polishing and surface appearance. Compared with corrosion-resistant mold steels such as 2316 and S136, NAK80 focuses on superior polishing performance, dimensional stability and faster mold manufacturing rather than corrosion resistance.

The biggest advantage of NAK80 is its ability to achieve high-gloss mirror surfaces and fine texture effects while avoiding heat treatment deformation. It is widely used for 3C electronic products, cosmetic packaging, household appliances and other plastic parts where appearance quality is critical.

This article explains NAK80 mold steel properties, chemical composition, machining requirements, polishing methods, applications and comparison with 718H, 2316 and S136 to help mold makers choose the right steel for high-gloss plastic injection molds.

Key Performance Advantages of NAK80 Mold Steel

NAK80 is designed for appearance-focused plastic molds where surface quality, dimensional stability and manufacturing efficiency are the main priorities.

1. Pre-Hardened Steel Without Additional Heat Treatment

NAK80 is supplied in a pre-hardened condition with a typical hardness range of 38-42 HRC.

Because the steel has already completed the aging hardening process before delivery, mold manufacturers can directly proceed with machining and polishing without:

• Vacuum quenching
• Tempering
• Additional aging treatment
• Heat treatment deformation correction

This significantly reduces production time and eliminates dimensional changes caused by post-machining heat treatment.

For precision plastic molds requiring short delivery cycles, NAK80 provides a practical alternative to fully hardened mold steels.

2. Excellent Mirror Polishing Performance

Mirror polishing is one of the most important advantages of NAK80.

Through refined steel manufacturing and low impurity control, NAK80 provides a clean internal structure with excellent polishing characteristics.

After proper polishing procedures, NAK80 can achieve:

• High-gloss mirror surfaces
• Low surface roughness
• Reduced polishing defects
• Improved appearance consistency

Compared with ordinary pre-hardened steels such as 718H, NAK80 delivers better surface brightness and fewer polishing problems such as uneven gloss and surface marks.

It is especially suitable for:

• Transparent plastic parts
• Glossy consumer electronics housings
• Cosmetic packaging components

3. Superior Texture Etching Performance

NAK80 has a uniform fine-grain structure, making it highly suitable for precision texture processing.

It performs well in applications requiring:

• Leather grain textures
• Matte surface patterns
• Fine decorative textures
• Brushed and micro-pattern designs

The uniform material structure helps maintain consistent etching depth throughout the mold cavity, reducing problems such as uneven patterns or unclear texture edges.

For high-end appearance molds, NAK80 provides better texture stability than many conventional pre-hardened steels.

4. Excellent Dimensional Stability

Unlike traditional hardened mold steels, NAK80 achieves hardness through precipitation hardening instead of quenching.

This results in:

• Lower internal stress
• Minimal deformation during machining
• Stable cavity dimensions
• Better precision retention during production

It is especially suitable for:

• Multi-cavity molds
• Precision inserts
• High-accuracy appearance components

5. Good Machinability Compared With Hardened Stainless Steel

NAK80 offers better machining performance than fully hardened stainless mold steels such as S136.

Advantages include:

• Lower cutting tool wear
• Easier CNC finishing
• Reduced processing time
• Lower manufacturing cost

This makes NAK80 an attractive choice when customers need premium appearance quality without the longer processing cycle of hardened stainless steels.

Limitations of NAK80 Mold Steel

Although NAK80 provides excellent surface performance, it is not suitable for every plastic molding application.

1. Limited Corrosion Resistance

NAK80 does not contain a high chromium stainless structure, meaning it does not provide strong rust resistance.

It is not recommended for molds using:

• PVC materials
• Corrosive additives
• Flame-retardant plastics
• Moisture-sensitive production environments

For corrosive plastic applications, stainless mold steels such as 2316 or S136 are usually more suitable.

2. Not Suitable for High-Temperature Applications

NAK80 is designed for standard plastic injection molding conditions.

For molds exposed to continuous high temperatures or aggressive engineering plastics, higher-temperature-resistant materials should be considered.

Chemical Composition of NAK80 Mold Steel

NAK80 uses a nickel-aluminum precipitation hardening system. Its alloy design focuses on polishing quality, dimensional stability and uniform microstructure.

Main Applications of NAK80 Mold Steel

NAK80 is mainly selected for non-corrosive plastic molds requiring excellent appearance quality.

1. 3C Electronic Appearance Molds

Typical applications include:

• Smartphone housings
• Tablet covers
• Laptop shells
• Smart wearable products
• Electronic decorative components

These products require:

• High gloss surfaces
• Precise texture patterns
• Stable dimensions

2. Cosmetic and Packaging Molds

NAK80 is widely used for appearance-focused packaging molds, including:

• Cosmetic bottle caps
• Beauty product containers
• High-end plastic packaging
• Decorative plastic components

Its mirror polishing capability helps achieve premium surface appearance.

3. Household Appliance Plastic Molds

Applications include:

• TV front covers
• Air conditioner panels
• Small appliance housings
• Decorative plastic parts

NAK80 helps maintain consistent gloss and texture across large mold surfaces.

4. Precision Mold Inserts and Trial Molds

Because no additional heat treatment is required, NAK80 is suitable for:

• Prototype molds
• Fast delivery molds
• Precision replacement inserts
• Small and medium batch production molds

NAK80 Machining and Processing Guidelines

CNC Machining

Recommended practices:

• Use sharp carbide cutting tools
• Avoid excessive cutting heat
• Perform fine finishing before polishing
• Maintain stable cutting conditions

Typical machining parameters:

• Cutting speed: 80-120 m/min
• Feed rate: 0.15-0.25 mm/r
• Cutting depth: 1-2.5 mm

EDM Processing

During EDM machining:

• Use stable low-energy discharge parameters
• Remove the EDM affected layer before polishing
• Avoid excessive heat input

Residual EDM layers may reduce final polishing quality and affect texture appearance.

Mirror Polishing

Recommended polishing process:

320# → 800# → 1500# → 5000# sandpaper → Diamond paste polishing

Important points:

• Do not skip polishing steps
• Avoid excessive pressure
• Maintain uniform polishing direction

Correct polishing methods are essential for achieving the full mirror capability of NAK80.

Welding and Maintenance

NAK80 requires proper maintenance because it is not stainless steel.

Recommendations:

• Use suitable NAK80 welding materials
• Apply anti-rust oil regularly
• Protect mold surfaces during storage

Do not perform unnecessary heat treatment, as it may damage the original precipitation hardening structure.

NAK80 vs 718H vs 2316 vs S136 Comparison

How to Choose NAK80 Mold Steel

Choose NAK80 when:

• The mold requires mirror polishing
• Fine texture quality is important
• Fast mold delivery is needed
• Plastic material is non-corrosive
• Heat treatment deformation must be avoided

Choose another steel when:

• The plastic contains corrosive additives → choose 2316 or S136
• Optical-level mirror performance is required → consider S136
• Surface requirements are ordinary → 718H may be more economical

Common Mistakes When Using NAK80

1. Using NAK80 for Corrosive Plastics

Because NAK80 is not stainless steel, corrosive materials may cause cavity rust and surface damage.

2. Performing Secondary Heat Treatment

Additional quenching or high-temperature treatment can destroy the original precipitation hardening structure.

3. Excessive Polishing Pressure

Over-polishing may damage surface uniformity and affect texture quality.

4. Selecting NAK80 for Every Appearance Mold

NAK80 is excellent for high-gloss applications, but stainless steels remain better choices when corrosion resistance is required.

Conclusion: Is NAK80 the Right Mold Steel for Your Project?

NAK80 mold steel is one of the best choices for high-gloss plastic appearance molds that require mirror polishing, fine texture etching and short production cycles.

Its pre-hardened 38-42 HRC condition eliminates heat treatment processes, while its refined structure provides excellent polishing quality and dimensional stability.

For non-corrosive 3C, cosmetic and household appliance molds, NAK80 offers a balanced solution between 718H and high-cost stainless mold steels such as S136.

KUTU supplies genuine ESR refined NAK80 mold steel with hardness reports, material certificates and customized cutting services. Contact us for professional material selection and processing support for high-gloss plastic mold projects.

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