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ColorFittings AN Bulkhead Lock Nuts are precision CNC-machined to securely fasten AN bulkhead fittings through firewalls, chassis panels, fuel cells, and custom fabrication projects. Designed to provide a tight, vibration-resistant hold, these bulkhead nuts ensure proper alignment and a secure mounting surface for leak-free AN plumbing systems.

Manufactured from aerospace-grade 6061-T6 billet aluminum and finished with ColorFittings’ proprietary anodizing process, these AN bulkhead nuts deliver superior strength, corrosion resistance, and long-term durability in high-heat, high-vibration racing and street performance environments.

Engineered for use with ColorFittings AN Union Bulkhead Fittings, these lock nuts provide the secure clamping force needed for fuel, oil, coolant, brake, transmission, and power steering applications. Ideal for motorsport builds, off-road vehicles, marine systems, and custom engine bay fabrication.

Complete your install with our matching AN Bulkheads, AN Fittings, and AN Assembly Tools for a clean, professional-grade plumbing solution built to perform.

Product Returns

Ordered the wrong part? Need to swap something out? No Problem! We accept returns provided they meet the following criteria:

  1. Purchased directly through ColorFittings at its physical storefront, through the ColorFittings website, or through an approved vendor within the last 90 days.
  2. The product is manufactured directly by ColorFittings, and not a resold item.
  3. The product is not a custom hose assembly or hose by-the-foot order
  4. Product may not be used or assembled.
  5. Product must be unopened and returned in resell-able condition. 
  6. Returned with prior approval from sales@colorfittings.com at the purchaser’s expense.
  7. By-the-foot hose orders and custom pre-assembled lines CAN NOT be returned.

Lifetime Warranty

ColorFittings confidently stands behind the products we manufacture and, as such, we offer a lifetime warranty on all products that are purchased directly or through approved vendors.

The lifetime warranty guarantees that products are free of manufacturing defects or flaws that directly impact functionality.  A free replacement will be provided as long as the following criteria are met:

  1. Purchased directly through ColorFittings at its physical storefront, through the ColorFittings website, or through an approved vendor.
  2. The product is manufactured directly by ColorFittings
  3. The product is not damaged due to improper installation, neglect, or abuse.
  4. Warranty claim and associated photos are pre-approved by sales@colorfittings.com prior to the failed product being shipped for return
  5. In some cases when electronic exchange of photos is insufficient, ColorFittings may request the product be shipped back at the purchaser’s expense.
  6. Products are used and assembled with other ColorFittings products when applicable (i.e. We will only warranty ColorFittings female hose ends when assembled with ColorFittings AN Hose).
  7. If the product in question is part of an oil cooler kit, catch-can kit, or other pre-assembled product, the vehicle should be diagnosed by qualified shop with documentation of failure being send to ColorFittings for approval prior to repair, disassembly, destructive-diagnosis, or corrective action.
  8. Customer is able to provide proof of purchase.

ColorFittings

ColorFittings is a specialist automotive brand that crafts high-quality AN fittings, hoses, adapters, oil cooler kits, and related hardware with a focus on performance and style. Founded in 2008 as a small enthusiast-run business, they’ve grown into a go-to source for builders who want precision-machined 6061-T6 billet aluminum components finished in vibrant anodized colors to match or enhance engine bays and plumbing systems

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