Masking for Anodizing

Anodizing is an electrochemical process that converts the surface of aluminium into a durable, corrosion-resistant oxide layer. Parts are immersed in a sulfuric acid bath — typically at 18–25 °C — and subjected to an electrical current for 10 to 60 minutes. Masking must protect threads, bearing surfaces, electrical contacts, and precision bores from the oxide layer, which would otherwise alter dimensions and insulate contact areas.

Unlike powder coating, anodizing does not involve high bake temperatures — but it demands excellent chemical resistance to sulfuric acid. At Masking Supply, we supply masking tapes, silicone plugs, silicone caps, and custom die-cut shapes specifically suited to anodizing environments. For complex geometries or production lines, we also engineer custom masking solutions from your part drawings.

Masking Products for Anodizing

  • Green polyester masking tape for powder coating and anodizing, temperature-resistant up to 200°C

    Polyester (PET) Masking Tape

    Chemical-resistant, no shrinkage, clean removal. The standard tape for anodizing masking — provides sharp boundaries and resists sulfuric acid baths.

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  • Polyimide masking tape for powder coating, PCB manufacturing, and electronics, temperature-resistant up to 260°C

    Polyimide (Kapton) Tape

    Excellent solvent and chemical resistance, rated to 260 °C (500 °F). Suitable for hard anodizing or processes involving elevated temperatures or aggressive chemistries.

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  • Dual-flanged silicone pull plug for masking weld nuts and through holes, temperature-resistant up to 250°C

    Silicone Masking Plugs

    Tapered, flange, step, and washer-pull designs for threads, blind bores, and grounding points. Flexible silicone maintains a tight seal during acid bath immersion.

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  • Silicone flanged cap for masking in powder coating and painting, temperature-resistant up to 250°C

    Silicone Masking Caps

    For studs, bolts, connectors, and protruding features. Chemical-resistant silicone rated to 250 °C (482 °F). Multiple sizes available.

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  • Custom Silicone Masking Parts

    Engineered-to-drawing silicone plugs, caps, and shapes for complex geometries. Cost-effective from 1,000–2,000 pieces.

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  • Custom silicone die-cuts in round shape manufactured by maskingsupply.com

    Custom Die-Cut Shapes

    Pre-cut PET tape discs, donuts, and custom profiles for masking circular surfaces, flanges, and complex anodizing boundaries.

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Custom silicone plug with cut-out for hanging solution made by maskingsupply.com

Need a Custom Masking Solution for Your Anodizing Line?

When standard plugs, caps, or tape shapes don’t fit your part geometry, we engineer custom masking solutions from your drawings. Custom silicone parts and die-cuts are typically cost-effective from 1,000–2,000 pieces — no large minimum orders required.

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Anodizing Masking Resources

Masking for Anodizing: Complete Guide

Material selection, chemical resistance, and best practices for anodizing masking.
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What Is Polyester (PET) Masking Tape?

Properties and applications of chemical-resistant PET masking tape.
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Silicone Rubber for Masking

Why silicone is the preferred material for chemical and high-temperature masking.
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How to Mask Complex Geometries

Techniques for masking parts with complex profiles and tight tolerances.
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Masking Die-Cuts: Standard and Custom Shapes

How precision die-cuts improve repeatability and reduce labour in production.
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Temperature Resistance Chart

Full material comparison chart for masking tapes, plugs, and caps.
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Not sure which masking product is right for your anodizing process?

Our masking specialists will help you select the right tapes, plugs, and caps — or engineer a custom solution for your specific part geometry and anodizing chemistry.

Contact our Experts