Weld-On Bungs - O2, Wideband, Fuel, Coolant & AN Fittings

What This Bungs Collection Covers

Bungs are weld-on or threaded foundation pieces for custom exhaust, fuel, coolant, oil, intake, chassis, and gauge work. This broad selection includes stainless steel O2 bungs, titanium AN bungs, aluminum stand-off bungs, threaded plugs, sensor ports, and weld fittings for fabricators building systems around exact tube size and thread requirements.

Exhaust Sensor and Wideband Bungs

Place sensors where they can read accurately

O2 and wideband bungs give an exhaust-mounted sensor a durable threaded home. Choose the correct thread, material, tube profile, and weld location. Sensor position should follow the gauge, ECU, or sensor manufacturer guidance and avoid areas where condensation can collect.

Fuel, Coolant, and Oil Ports

Build a reliable threaded connection

AN and NPT weld bungs allow custom tanks, catch cans, radiator pipes, fuel cells, and oil pans to use serviceable hose connections. Match the bung material to the host component and choose a thread that fits the planned fitting, sensor, or plug.

Material Selection for Fabrication

Match the alloy to the job

Stainless steel bungs suit stainless exhaust and many fluid fabrication projects. Aluminum bungs are useful on aluminum tanks and intercooler plumbing. Titanium bungs are intended for titanium fabrication and require suitable welding technique.

Tube, Chassis, and Mounting Bungs

Add strong attachment points

Stand-off bungs and threaded tube bungs provide clean mounting points for brackets, panels, and fabrication fixtures. Confirm tube wall thickness, thread direction, and required engagement depth before welding.

Welding and Finishing Details

Prepare the assembly before final welds

Mock up sensor clearance, fitting clocking, and tool access before tack welding. Protect threaded portions from weld spatter, allow the part to cool naturally, and chase threads only if needed after the work is complete.

Top Bung and Fabrication Brands

• Vibrant. Stainless, aluminum, and titanium weld bungs
• Ticon Industries. Titanium bungs and motorsport fabrication hardware
• Stainless Bros. Cast stainless O2 sensor bungs
• Fragola. AN weld bungs and plumbing components
• Aeromotive. Fuel system fabrication hardware
• Radium Engineering. Fuel and fluid system fittings
• Wehrli. Diesel sensor and fabrication components
• Killer B Motorsport. Performance engine fittings and plugs
• RockJock. Threaded chassis and suspension bungs
• Kooks. Exhaust fabrication components
• MagnaFlow. Exhaust repair and installation hardware
• Earls. Fluid transfer adapters and fittings
• Aeroquip. Hose and tube connection components
• HPTuners. Sensor support hardware for custom builds
• Garrett. Turbocharger plumbing and fabrication parts

How to Choose the Correct Weld-On Bung

• Confirm the host material such as stainless steel, aluminum, mild steel, or titanium
• Match the thread to the sensor, plug, or AN fitting that will be installed
• Measure tube diameter and choose a saddle style bung when needed
• Verify wall thickness and leave enough material for safe thread engagement
• Use an O2 bung specified for the sensor thread and sealing style
• Select a plug or cap that matches the bung when the port will not be used
• Plan sensor angle and access before welding an exhaust bung
• Keep fuel, oil, and coolant bungs away from interference points and heat sources
• Use the appropriate welding process and filler for the materials involved
• Test fit the final fitting after cooling and inspect the weld for complete fusion

Common Questions

What is a weld-on bung?

A weld-on bung is a threaded fitting that is attached to a fabricated component to create a serviceable port for a sensor, plug, hose fitting, or mount.

Where should an O2 sensor bung be installed?

Follow the sensor and engine management guidance for placement. The bung should provide sensor clearance and avoid a location that traps moisture.

Can I weld an aluminum bung to steel?

No. Match the bung material to the component being welded or use a suitable transition design designed by a qualified fabricator.

What does AN mean on a weld bung?

AN identifies a standardized fluid fitting size and thread family used in performance plumbing. Confirm the exact male or female configuration before ordering.

Do wideband and narrowband O2 sensors use the same bung?

Many use a common M18 by 1.5 thread, but always verify the sensor specification before choosing a bung or plug.

Should I install a bung before or after coating an exhaust part?

Weld and finish the bung before final coating whenever possible. Coatings near a weld area can be damaged by heat.

What is a stand-off bung used for?

A stand-off bung creates a threaded mounting point for brackets, panels, or accessories while spacing the attachment away from the base material.

Can I plug an unused O2 bung?

Yes, use a correctly threaded plug designed for exhaust temperature and material requirements.

How do I choose a tube bung size?

Match the outside diameter, wall thickness, thread size, and left or right hand thread requirement to the fabrication design.

Can Black Ops Auto Works help identify the right bung?

Yes. Provide the host material, tube size, thread needed, and planned fitting or sensor for fitment support.

Why Buy Bungs from Black Ops Auto Works

Black Ops Auto Works stocks 123 Bungs SKUs with real fitment data, competitive pricing, and support from staff who build these vehicles themselves. Products are filterable by year, make, model, trim, engine, and drivetrain to confirm the correct application before ordering.

For focused shopping, browse our Fabrication, Fittings, Headers & Manifolds, Exhaust Systems, Vibrant, Ticon.