Quantity Your Price
1-9 $38.95
10+ $35.06

C73-776

2-3/4 in. RED FILL CAP WITH ALUMINUM WELD BUNG

2-1/4-10 Straight Thread
2-3/4 in. Outside Diameter Bung
5/8 in. Bung Height

This assembly includes a weldable aluminum bung. A convenient stepped shoulder is machined in the base of the bung, acting as a positioning locator during fabrication. This bonus feature holds the bung in place while welding in a hole on a flat surface, or in the end of tubing when building a filler neck extension. This is a great anti-frustration feature that is appreciated by the finish installer.

The lightweight, non-vented cap features positive grip finger notches that is easy to get a hold of. The 6061-T6 billet aluminum cap is CNC machined for accuracy with a lightweight, attractive design and features quick-starting coarse threads. Each is standard with a special positive sealing "radial squeeze" Buna O-ring, which also holds the cap secure. Billet Aluminum Fill Caps is a Pro-werks specialty.

Easy Turn Fill Caps are available in variety of sizes to fit most any application, big or small. 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, silver, or beautifully Micro-polished aluminum. 

Proudly made in the USA.




Q:

How much do I need to tighten a fill cap?

A:

It is not necessary to bottom the fill cap into the receiving bung. Adequately seating the O-ring to make a seal is all that is required. The radial squeeze action on the O-ring creates a strong seal and helps to keep the cap from coming loose.

 



Q:

What should I use to lubricate a Buna O-ring?

A:

A light coating of Dielectric grease works very well as O-ring lubricant.

 



Q:

What is Buna and is it compatible with my fluid?

A:

Buna is a universal composition synthetic rubber, a standard of plumbing related products because it is compatible with many fluids. Due to the complex chemistry of modern day performance oils and fuels, you may find it necessary to replace Buna components with a material that is compatible with the unique chemistry of your specific fluids.

 



Q:

How do I weld my bung properly?

A:

It is a good practice to apply several small, equally spaced tacks to minimize the potential for distortion. The bung should also be preheated and the weld should be kept small to reduce natural weld shrinkage.

 



Q:

The cap won't fit after welding my bung. How do I fix this?

A:

Minor distortion of the bung from improper welding can often be addressed by applying a small amount of fine grit lapping compound to the cap threads and turning the cap back and forth in the bung to resize the threads. Do not force the process, be patient and thoroughly clean both sets of threads after the desired fit is achieved.

 

2-3/4 in. Red Fill Cap: C73-781
Outside Grip Diameter: 3.200 in.
Height: 0.312 in.
Thread: 2-1/4-10
Height: 0.625 in.
Inside Grip Diameter: 2.750 in.
Aluminum Weld-In Bungs: C73-787
Outised Diameter: 2.75 in.
Thread: 2-1/4-10
Height: 0.625 in.
Diameter: 2.620 in.
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