• fuel tank caps, radiator caps, and brake fluid reservoir caps

    Custom Billet Aluminum Caps

    Custom aluminum caps manufactured by CNC machining or casting + CNC finishing for fuel, oil, radiator and fluid systems.

    We manufacture custom CNC billet aluminum caps for automotive and motorcycle brands — including fuel caps, oil filler caps, radiator and coolant caps, and brake or clutch reservoir caps.

    Our engineering team supports drawing-based customization, tolerance control, fast prototyping, anodized finishes, and laser logo engraving — from prototype to scalable OEM production.

  • Cap Applications We Manufacture

    CNC machined billet aluminum fuel caps

    Fuel Caps

    Custom aluminum fuel caps manufactured by CNC machining or casting + CNC finishing for automotive and motorcycle brands.

    CNC machined billet aluminum fuel caps

    Oil Filler Caps

    Precision aluminum oil filler caps with custom thread specifications and anodized surface finishes.

    Anodized aluminum radiator caps manufacturing

    Radiator & Coolant Caps

    Radiator caps and coolant reservoir caps with engineered sealing structure and surface finishing options.

    aluminum reservoir caps

    Brake & Clutch Reservoir Caps

    CNC aluminum caps designed for hydraulic brake and clutch reservoir systems.

  • Custom Aluminum Caps for Automotive & Motorcycle Applications

    Custom aluminum caps are widely used in automotive and motorcycle fluid systems, including fuel tanks, engine oil systems, radiator cooling systems, and brake hydraulic reservoirs.

    Wometal manufactures custom aluminum caps through CNC machining, die casting, and casting with CNC finishing to meet different production volumes and cost requirements.

    Our products include:

    • Custom fuel caps
    • Oil filler caps
    • Radiator caps
    • Coolant reservoir caps
    • Brake reservoir caps

    We support drawing-based customization and OEM manufacturing for automotive and motorcycle brands worldwide.

  • Why Aluminum Caps

    Custom aluminum caps offer improved durability, sealing performance, and premium appearance compared to traditional plastic caps.

    • High dimensional accuracy
    • Reliable sealing performance
    • Durable anodized surface finish
    • Corrosion resistance
    • Suitable for OEM and performance applications

  • Customization & Manufacturing Options

    We support full customization from material selection to manufacturing process, surface finishing, and branding.

    Material & Manufacturing

    • 6061 / 7075 aluminum
    • CNC billet machining
    • Aluminum die casting
    • Casting + CNC precision finishing

    Surface Finishing

    • Anodizing (multiple color options)
    • Brushed or polished finish
    • Powder coating options

    Branding & Design

    • Laser logo engraving
    • Custom surface patterns
    • Private label manufacturing

    Engineering Support

    • Drawing-based customization
    • Thread specification review
    • O-ring / gasket sealing design
    • Prototype engineering support

    Production Capacity

    • Prototype development
    • Small batch production
    • OEM batch manufacturing

  • Custom Cap Development Process

    1

    Project Inquiry

    Share your drawing, sample, or technical requirement.
    We review application, material preference, surface finish, and expected quantity.

    2

    Technical Evaluation

    Our engineering team reviews:

    • Thread specification
    • Sealing structure (O-ring / gasket)
    • Tolerance requirements
    • Machining feasibility
    • Surface finishing process

    Optional design optimization suggestions can be provided if needed.

    3

    Quotation & Lead Time

    After technical confirmation, we provide:

    • Unit price
    • Tooling cost (if required)
    • MOQ information
    • Prototype and mass production lead time

    4

    Prototype Development

    Prototype samples can be produced for testing and validation.

    5

    Batch Production

    After sample approval, we proceed with controlled batch production. Manufacturing includes CNC machining, die casting, and casting + CNC finishing.

    6

    Global Delivery & Support

    Products are packed according to international export standards.

    We support international shipping and ongoing production programs for repeat orders.

  • Manufacturing Capability

    Our manufacturing capabilities for aluminum caps include:

    • CNC aluminum machining
    • Aluminum die casting
    • Casting + CNC precision finishing
    • Surface finishing and anodizing
    • Laser logo engraving

    We support prototype development, small batch production, and OEM manufacturing for global automotive and motorcycle brands.

  • Start Your Custom Cap Project

    Send us your drawing or technical requirement. Our engineering team will review your project and provide quotation and lead time. We’ll respond with technical feedback and lead time after drawing review

  • Frequently Asked Questions

  • Related Resources / Learn More About Caps

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    March 31, 2025
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    April 25, 2024
    Aluminum Alloy Oil Tank Cover Base Casting
    February 19, 2024
    The Automotive Fuel Tanks
    September 20, 2023
    The classic Aston & Monza filler caps
    September 20, 2023
    The main role of the fuel filler cap
    September 20, 2023
    Gas Cap Classification According to Model
    March 2, 2023
    Requirements for automobile fuel tank cap and refueling port.
    April 21, 2025
    What does an automobile radiator cap do?
    May 10, 2024
    Racing Car Oil Tank Caps For Motorsports
    February 19, 2024
    History of Gas Cap Development
    February 19, 2024
    Gas cap replacement
    September 20, 2023
    The Different Gas Caps
    September 20, 2023
    Practical tips for car gas cap
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