Filler Cap and Bung Vented

Vented Filler Cap & Bung Kit – 1.25"-12 Thread, Compact Design

This vented filler cap and bung kit is a compact, functional solution for gas tanks, oil tanks, or any fluid container that requires internal venting. Built around our trusted, long-standing 1.25"-12 thread design, this version includes a small .040" vent hole and an internal brass vent fitting to reduce the chance of fluid seepage while still allowing pressure equalization.

The cap is made from lightweight 6061 aluminum with a low-profile 1.5" outer diameter, offering a sleek, minimal look without sacrificing function. The weld-in bung is available in your choice of mild steel, 6061-T6 aluminum, or 304 stainless steel, giving you the flexibility to match your fabrication material.

Despite its compact size, the filler hole is large enough for most gas pump nozzles or oil fill systems, and the included fuel-resistant O-ring ensures a tight, leak-free seal.

Product Features:

• Thread Size: 1.25"-12 – industry-standard fit

• Cap Material: 6061 aluminum, 1.5" outer diameter

• Bung Flange O.D.: 1.75", stepped down to 1.5" for easy welding

• Vent System: Built-in .040" vent hole with internal brass vent fitting

• Seal: Replaceable fuel-resistant O-ring

• Bung Material Options: Mild Steel, 6061-T6 Aluminum, or 304 Stainless Steel

• Applications: Gas tanks, oil tanks, or any vented fluid reservoir

• Made in the USA

• Sold as a complete kit (1 filler bung + 1 vented cap)

Built for clean looks, reliable performance, and seamless integration into custom or OEM-style tanks.