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Many combinations, Several colors and Amazing finishes.

Custom-fabricated tanks, Fuel cells, Rear End housings, Valve covers, Overflow tanks, Intercooler ice boxes, Ballast tanks, Inspection viewing ports

19 products

Pro-werks Easy Turn Filler Cap with Aluminum Weld Bung

Pro-werks Easy Turn Filler Cap with Steel Weld Bung

Pro-werks Easy Turn Filler Cap with Stainless Steel Weld Bung

Pro-werks Easy Turn Filler Cap with Aluminum Bolt-On Bung

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Pro-werks Easy Turn Fuel Cell Filler Cap with Lanyard Boss and 6-Bolt Aluminum Fuel Cell Bung

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Pro-werks Easy Turn Fuel Cell Filler Cap with Lanyard Boss and 12-Bolt Aluminum Fuel Cell Bung

Pro-werks Easy Turn Filler Cap with Aluminum Remote Mount Bung

Pro-werks Easy Turn Filler Cap with Aluminum Recessed Remote Mount Bung

Pro-werks Easy Turn Filler Cap with O-Ring

Pro-werks Weld-On Fill Cap Bung

Pro-werks Bolt-On Aluminum Filler Cap Bung

Pro-werks Bolt-On Fuel Cell Aluminum Filler Cap Bung

Pro-werks Remote Mount Aluminum Filler Cap Bung

Pro-werks Lanyard Chain Kit, Stainless Steel

Pro-werks Easy Turn Filler Cap Replacement O-Ring, Buna Material

Pro-werks Easy Turn Filler Cap Bolt-On Bung Replacement O-Ring, .103 Inch Thick Buna Material

Pro-werks Easy Turn Filler Cap Bolt-On Fuel Cell Bung Replacement Gasket, 1/16 Inch Thick Buna Material

Pro-werks NPT Female Weld Bung

Pro-werks AN Thread Weld Bung

Fill Caps and Bungs

Safe. Secure. Sexy.

Turn heads while working on your race car or hot rod with Pro-werks' signature Easy Turn Fill Caps. Once you've added one of these amazing assemblies, you'll want to install one at every location possible. And you may find yourself checking things more often, just to get your hands on the Easy Turn cap again!

These lightweight, non-vented Pro-werks Fill Caps feature deep finger notches for a positive and comfortable grip, this design is another Pro-werks innovation, appreciated by everyone who uses them.

 

 

Precision Matters.

We start with American melt 6061-T6 billet aluminum: it is precision CNC machined to exacting standards for proper fit and to create the foundation for obtaining amazing finishes and performance.

This design uses a "radial squeeze" action on the Buna O-ring for a secure seal. Precision machined quick-start coarse threads make using these caps a breeze.

The large selection of Pro-werks mounting bungs are crafted fron Steel, Aluminum or Stainless Steel and available in both Weld-in and Bolt-in styles.

 

Great Caps. Great Colors.

To compliment the color combination of your project, the caps are finished off in Pro-werks Brilliance anodized colors in your choice of Black, Red, Blue, or beautifully Micro-Polished aluminum - the finishes ar impeccable!

 

The Right Size Matters.

Easy Turn Fill Caps come in many sizes and are packaged as complete assemblies with your choice of one of the many versatile mounting options, or each component is also available separately.

capsizes Easy Turn Fill Cap with O-Ring

Popular uses for Easy Turn Fill Caps include:

  • Custom-fabricated tanks
  • Fuel cells
  • Gas tanks
  • Rear End housings
  • Valve covers
  • Overflow tanks
  • Ice boxes for intercoolers
  • Ballast tanks
  • Inspection viewing ports


Proudly Made in the USA

Be sure to check out the entire line up - Billet aluminum Easy Turn Fill Caps are a Pro-Werks specialty.

You can always count on Pro-Werks to do it right!

 

Finish Your Tank

We also offer a full line of weld plumbing bungs to complete your project.

FemaleSteelFull NPT Female Weld In Bung

Click the images above to view all the options.

 

PRO TIP:  How to Calculate Tank Capacity

You can calculate how many gallons of fluid a tank will hold by dividing the total cubic inch volume by 231. As an example a basic rectangular shaped tank measuring 12"(L) x 12"(W) x 10"(H) = 1440 cubic inches. The next step is to divide the total volume of 1440 cubic inches by 231 = 6.23 gallons.

If your tank is an irregular shape, or has unique features, calculate the cubic inch volume of those areas also, then add or subtract the values to arrive at the total cubic inch volume of your custom fabricated tank.

Note: Welding should always be performed by a qualified welder.

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