Filler Caps

Products List

Filters

Sort By:

Display Type:
  • Product
  • Qty in Cart
  • Quantity
  • Price
  • Subtotal
  • Non-vented filler cap and bung kit with 1.25"-12 thread for custom tanks Compact aluminum non-vented filler cap with weld-in bung – steel, aluminum, stainless

    Filler Cap and Bung

    FCwB
    $25.75 - $29.75
    Non-Vented Filler Cap & Bung Kit – 1.25"-12 Thread, Compact Design The non-vented filler cap and bung kit is a compact and clean solution for gas tanks, oil tanks, and fluid reservoirs where external venting is preferred or required. Using our...
    Choose Options
    Qty in Cart: 0
    Quantity:
    Price:
    $25.75 - $29.75
    Subtotal:
  • Vented aluminum filler cap with weld-in bung and brass vent fitting, 1.25"-12 thread, compact design for gas or oil tanks. Compact vented filler cap and weld-in bung kit with internal brass vent, available in steel, aluminum, or stainless steel.

    Filler Cap and Bung Vented

    FCBV
    $31.75 - $36.50
    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,...
    Choose Options
    Qty in Cart: 0
    Quantity:
    Price:
    $31.75 - $36.50
    Subtotal:
  • Non-vented brass cap and weld-in bung kit for custom oil or overflow tanks, threaded 1.250"-12 with replaceable O-ring. Non-vented brass cap and weld-in bung kit for custom oil or overflow tanks, threaded 1.250"-12 with replaceable O-ring.

    Brass Filler Cap and Bung

    BFCB
    $44.75 - $47.75
    Brass Filler Cap & Weld-In Bung – For Oil or Fluid Tanks Upgrade your custom build with this premium Brass Filler Cap and Bung Kit, ideal for use on oil tanks, overflow reservoirs, or any non-vented fluid container. This setup provides a clean,...
    Choose Options
    Qty in Cart: 0
    Quantity:
    Price:
    $44.75 - $47.75
    Subtotal:
  • Solid brass filler cap with tall weld-in bung for gas or oil tanks, vented or non-vented, 1.25"-12 thread, steel or aluminum construction. Brass fuel or oil filler cap with tall weld-in neck, available in vented or non-vented styles, fits custom tanks with 1.25"-12 thread.

    Brass Filler Cap with Tall Bung

    BTFCB
    $49.50 - $57.00
    Brass Filler Cap with Tall Weld-In Filler Neck – Vented or Non-Vented Add classic style and versatility to your custom build with this Brass Filler Cap and Tall Weld-In Filler Neck. Ideal for oil tanks, gas tanks, or any steel or aluminum fluid...
    Choose Options
    Qty in Cart: 0
    Quantity:
    Price:
    $49.50 - $57.00
    Subtotal:
  • Brass vented filler cap with 1.25"-12 weld-in bung, includes internal vent fitting and O-ring seal for oil or gas tank applications. Compact brass filler cap and steel weld-in bung with vented design, fits gas and oil tanks, 1.25"-12 thread, made in the USA.

    Brass Vented / Filler Cap and Weld in Bung

    BVF
    $52.00 - $55.00
    Brass Vented Filler Cap & Bung Kit – 1.25"-12 Thread Back by popular demand, we’re now offering a vented filler cap and bung kit featuring a solid brass cap. Built on the same trusted platform as our original design, this version combines...
    Choose Options
    Qty in Cart: 0
    Quantity:
    Price:
    $52.00 - $55.00
    Subtotal:
  • Tall weld-in filler neck with aluminum cap, 1.25"-12 thread, vented or non-vented, mild steel bung for gas or oil tanks, made in the USA. Aluminum filler cap with tall mild steel weld-in neck, 1.25" thread, for custom gas or oil tanks, available vented or non-vented.

    Aluminum Filler Cap with Tall bung

    ATFC
    $30.75 - $38.50
    Tall Weld-In Filler Neck with Aluminum Cap – Vented or Non-Vented This tall weld-in filler neck and aluminum cap kit offers added height and versatility over our standard filler bung setup. Designed for custom applications like oil tanks, gas...
    Choose Options
    Qty in Cart: 0
    Quantity:
    Price:
    $30.75 - $38.50
    Subtotal:
  • Close-up of Bung King solid brass gas cap with knurled edge and O-ring seal. Solid brass Harley gas cap installed on a fuel tank, showing low-profile fit and knurled grip.

    Brass Gas Cap OEM HD Tank

    BGCOEM
    $69.95 - $139.90
    Brass Gas Cap – Fits Harley-Davidson Models from 1986 to Present Give your Harley-Davidson a custom look with our precision-crafted Brass Gas Cap. Designed to fit all HD models from 1986 to the present, this cap uses the OEM-style thread and O-ring...
    Choose Options
    Qty in Cart: 0
    Quantity:
    Price:
    $69.95 - $139.90
    Subtotal:
  • brass oil cap threaded 1-1/4" x 12 sealed brass oil cap threaded 1-1/4" x 12 sealed

    Brass Oil / Filler Cap

    BOFC
    $33.00
    By popular demand we are now making a Brass version of our common Filler Cap. These can be used for oil tanks or any other fluid container that requires a non vented cap. These caps use the same standard bung we have made for years the 1 1/4 x 12 thread...
    Add to Cart
    Qty in Cart: 0
    Quantity:
    Price:
    $33.00
    Subtotal:
  • brass vented filler cap and weld in bung  gas steel stainless aluminum brass vented filler cap and weld in bung  gas steel stainless aluminum

    Brass Vented / Filler Cap

    BVFC
    $39.00
    By popular demand we are now making a Brass Vented version of our common Filler Cap and Bung Can be used for gas tanks oil tanks or any other fluid container. These caps use the same standard bung we have used for years so if you want to upgrade to a...
    Choose Options
    Qty in Cart: 0
    Quantity:
    Price:
    $39.00
    Subtotal:
  • WELD in gas tank oil tank filler bung catch puke tank steel aluminum stainless steel

    Weld in Filler Bung

    FB
    $14.50 - $17.50
    These are our weld in filler bungs, used with all of our vented and non vented caps. 1 1/4" x 12 thread 1 3/4" flange OD 1 1/2" stepped down OD Available in Mild Steel, Aluminum, or Stainless Steel Sold each
    Choose Options
    Qty in Cart: 0
    Quantity:
    Price:
    $14.50 - $17.50
    Subtotal:
  • Tall weld-in filler bung made from mild steel, 1.25"-12 thread, 1.25" tall, fits Bung King filler caps for gas or oil tank fabrication. Mild steel weld-in filler bung with 1.25"-12 thread, taller profile for custom oil or gas tanks, compatible with brass or aluminum caps.

    Tall Filler Bung

    TFB
    $13.75 - $14.75
    Tall Weld-In Filler Bung – 1.25"-12 Thread, Mild Steel This tall weld-in filler bung is a modified version of our popular flanged filler bungs, designed for builders who want a bit more height on their filler neck. With an overall height of 1.25",...
    Choose Options
    Qty in Cart: 0
    Quantity:
    Price:
    $13.75 - $14.75
    Subtotal:
  • Replacement Filler cap O-ring

    Replacement Filler cap O-ring

    oring
    $0.39
    This is a replacement O-ring for all of our vented and non vented filler caps. Made from fuel and oil resistant rubber for a long service life. -sold each for $0.39
    Add to Cart
    Qty in Cart: 0
    Quantity:
    Price:
    $0.39
    Subtotal:
  • stock oem gas cap weld in screw type filler bung neck gas tank steel Harley Davidson stock oem gas cap weld in screw type filler bung neck gas tank steel Harley Davidson

    OEM Gas Tank Bung

    OEMGTB
    $14.00
    This is an OEM style weld in gas tank bung, the same one used on all of the later Harley Davidson Tanks. Permits the use of factory or the vast variety of aftermarket replacement gas caps on the market. The bung is made of mild steel and has the threads...
    Choose Options
    Qty in Cart: 0
    Quantity:
    Price:
    $14.00
    Subtotal:
  • 1/8 npt screw in vent fitting SINTERED BRASS

    1/8" male NPT Vent Fitting

    BVENT18
    $2.49
    This is a 1/8" male NPT fitting with a brass screen/filter. We commonly use these for our filler caps to provide a vent but cut down on the amount of fluid seapage from having a vented hole in a fluid container. They are oil and fuel resistant for a long...
    Add to Cart
    Qty in Cart: 0
    Quantity:
    Price:
    $2.49
    Subtotal:
  • Total: items /

Adding your products to cart

 

 

Filler Caps – Secure, Leak-Proof Solutions for Custom Tanks


Bung King’s filler caps are the perfect solution for sealing custom fuel tanks, oil tanks, and other fluid containers. CNC-machined in the USA from high-quality steel, stainless steel, aluminum, and brass, these filler caps ensure a secure, leak-proof connection that keeps your tank’s contents safe and secure.

 

Ideal for custom motorcycles, choppers, and hot rods, our filler caps are available in a range of sizes and finishes, including stainless steel, aluminum, and brass. Whether you're building a new tank from scratch or upgrading an existing one, these caps offer superior sealing and a clean, professional finish for your custom build.

 

Key Features:

CNC-machined from steel, stainless steel, aluminum, and brass for durability and precision
Leak-proof design ensures a secure, tight seal for custom tanks
Available in various sizes to fit different tank applications
Ideal for custom motorcycles, choppers, hot rods, and other custom fluid containers
Weld-ready for easy installation and professional results
Manufactured in the USA for top-quality craftsmanship and reliability


When it comes to sealing your custom fuel or oil tanks, Bung King filler caps offer the perfect combination of performance, durability, and style.