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Made in the USA

Pro-werks Weld-On Fill Cap Bung

Sale price $15.99 USD
Part # C73-747
Select Bung Material First
Select Fill Cap Size Second
Select Bung Height Last

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Pro-werks Fill Cap Bungs are available separately without the cap. This selection of weld-able bungs includes several different heights; available in Steel, Aluminum or Stainless Steel materials.

Precision machined and weld-able with ample cross section to assist in reducing potential distortion from welding, and sized properly for the "radially squeezed" O-ring standard of the Pro-werks Easy Turn Fill Cap.

The bolt-on style bung selection is also available, and do not require welding; select anodized colors are available and include mounting hardware - so you won't need to run all over town looking for it!

Get a Step Ahead

Your fabricator will appreciate the stepped shoulder at the base of the bung, it serves as a positioning locator. This feature holds the bung in place while welding in a hole of a flat surface, or in the end of tubing when constructing a filler neck extension.

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

Pro-Werks weld-on fill cap bung stepped shoulder positioning detail

Perfect for Custom Tank Fabrication

Pro-Werks fill cap bung installed on custom race fuel cell

Pro-Werks weld-on bung custom tank fabrication application

Great Filler Caps - Great Colors

To compliment the color coordination 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 are impeccable!

Pro-Werks Easy Turn Fill Cap anodized color options — Black, Red, Blue, Polished Aluminum

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.

Pro-Werks Easy Turn Fill Cap size comparison chart

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!

Pro-Werks Made in the USA

Customer Comments:

"I use your bolt on caps and bungs on my carbon fiber Cummins common rail valve covers. Love the quality. Thank you."
– Randy Davis, Owner of OldSkoolFab, Inc.

"I upgraded my fuel cell to an Easy Turn fill cap assembly. It wasn't long until all my friends did the same. Great product!"
– As shared with us at the PRI Show

Frequently Asked Questions

Q: How do I properly weld my bung?
A: Apply several small, equally spaced tacks and preheat before welding. Keep the weld small to minimize potential distortion or shrinkage.

Q: If my threads are tight after welding, how do I fix it?
A: The solution is simple. Apply a small amount of fine grit lapping compound to the threads then turn the cap back and forth in the bung until the desired fit is achieved. Be patient−do not force the process. Thoroughly clean both sets of threads before use.

Pro-Werks Fill Cap Product Brochure 2023

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