Aluminum Tooling Texture Guide for Rapid Prototypes and Low-Volume Production

When designing a plastic part for injection molding, surface texture often gets treated a a cosmetic afterthought. But it can play a major role in both function and manufacturability, especially if you’re evaluating textures early in the development process.

At UPTIVE (including out tooling and molding division, Phoenix), we offer aluminum tooling as a fast, cost-effective option for prototyping and low-volume production. And yes, aluminum molds can be textured, giving you valuable insight into how your final part will look, feel, and perform.

Here’s everything you need to know about aluminum tooling textures.

Why Add Texture to Aluminum Tooling?

Aluminum tools are typically used for short-run or prototype production, so many customers assume that texture doesn’t apply. But in reality, adding texture can be a critical step in part development, especially when you’re trying to simulate production conditions.

Benefits of adding texture to prototype molds include:

• Aesthetic realism – helps stakeholders visualize the finished product
• Functionality – improved grip, reduces glare, or creates specific tactile experiences
• Mold release – textured surfaces often reduce vacuum pressure and allow parts to release more easily
• Defect masking – hides weld lines, sink marks, or flow imprefections that might be more visible on smooth arts

With aluminum tooling, these textures are machined directly into the mold surface, so you get quick-turn parts with real-world surface finishes.

Learn more about aluminum tooling >

How Aluminum Tooling is Textured

In production steel tooling, surface texture is usually applied through chemical etching or EDM. But aluminum doesn’t respond well to these processes, so a different approach is required.

At UPTIVE, aluminum tooling is textured using CNC machining or bead blasting.

• Bead blasting offers a uniform, matter appearance and removes visible tool marks from machined surfaces
• CNC-machined textures simulate standard Mold-Tech patterns using specialized bits and engraving techniques. These are not exact replicas of Mold-Tech finishes, but they provide an effective approximation, which is ideal for prototypes.

Standard Surface Finish Options

Below are the most common finish options we offer for aluminum prototype tooling. These follow industry conventions and allow for consistency between prototype and production parts.

PM-F0: As-Machined/Non-Cosmetic

This is the default finish after CNC machining. You’ll see visible tool paths and some variation in surface quality.

• Use case: non-cosmetic internal parts or early prototypes
• Pros: fastest and least expensive
• Cons: not aesthetically pleasing

PM-F1: Bead Blast/Low-Cosmetic

A fine bead blast is applied to remove tool marks and deliver a smooth, matte finish

• Use case: general-use prototypes, components requiring improved appearance
• Surface feel: uniform and low-gloss
• Pros: affordable and quick to apply
• Cons: may not fully replicate production-level texture

PM-T1 to PM-T5: Mold-Tech Style Finishes

These textures simulate standard Mold-Tech patterns through direct machining into the aluminum. They’re not chemically etched, so they’re shallower and less complex, but they offer a strong visual and tactile reference.

Finish	Description
PM-T1	Fine matte texture
PM-T2	Light grain texture
PM-T3	Medium grain, leather-like texture
PM-T4	Deep grain for visual and tactile appeal
PM-T5	Heavy texture, ideal for grip surfaces

• Best for: prototypes requiring realistic texture representation
• Note: heavier textures may require additional draft angles

SPI Surface Finishes (A-1 to D-3)

SPI (Society of the Plastics Industry) finishes are an industry-standard classification used across injection molding, including aluminum tooling. These finishes are achieved using polishing or abrasion techniques on mold surfaces.

Finish	Process	Result
A-1	Diamond buff	High-gloss, mirror-like finish
A-2	Grade #6 grit emery	Glossy surface
A-3	Grade #15 grit emery	Smooth, high-gloss surface
B-1	600 grit paper	Semi-gloss with visible polishing marks
B-2	400 grit paper	Low-gloss surface
B-3	320 grit paper	Satin finish
C-1	600 stone	Matte finish
C-2	400 stone	Medium matte
D-1 to D-3	Dry blast (glass beads, aluminum oxide)	Coarse textures and rough finishes

Use Cases:

• A finishes are typically used for clear parts or high-end cosmetic components
• B and C finishes are ideal for most general-purpose applications
• D finishes simulate molded-in rough textures and can improve grip or visual interest

Design for Texture: Key Considerations

Adding texture to your tooling affects both the design adn manufacturability of your part. Here are some things to consider:

Add More Draft

Textured surfaces create friction during ejection, so more draft is needed than with smooth surfaces.

Minimum draft:

• Light textures: 1° per side
• Heavy textures (like PM-T5 or D-3): 2-3° per side

Expect Slightly Longer Lead Times

More complex textures (especially engraved Mold-Tech or SPI D-series finishes) require additional machining or blasting time.

Balance Aesthetics and Function

Certain textures can improve part appearance while also offering better grip or easier release, choose one that works for both.

Other Considerations When Texturing Aluminum Tools

Here are a few additional tips when designing parts with texture in mind:

• Texture will affect light reflection. Gloss levels can vary significantly depending on the finish you choose
• Wall thickness might look visually thinner or thicker based on the texture and lighting
• Texturing adds machining time, so heavier or more detailed textures may slightly increase tool lead times and costs, but far less than a steel tool would

Get Expert Help on Your Next Project

If you’re considering aluminum tooling for your next prototype or low-volume run and want to explore texture options, we’re here to help. UPTIVE offers fast lead times, deep design-for-manufacturing expertise, and the flexibility to test real-world design features, without the time or cost of steel.

Need to talk it through? Contact our team to discuss your texture and tooling needs.