AC PERFORMANCE Steel Female 1/4 NPT Weld-On Bung (1/4"), pack of 2
Reviews
Product description
What it is and what it’s for
This AC PERFORMANCE steel female 1/4 NPT weld-on bung is a practical fitting if you’re building or modifying a fuel-related setup and you want a threaded connection where you can weld a port into a manifold, pipe, or tank. It’s supplied as a pack of 2, so you’re covered if you’re doing a matched pair, replacing more than one section, or simply want a spare.
On paper, the idea is straightforward: you weld the bung in place, then you can use the female 1/4" NPT thread to connect compatible parts. The description also points to common automotive-style applications such as fuel and tank work, along with examples like intercooler piping, intake manifolds, or even a custom overflow tank. That gives you a decent sense of the intended use—this isn’t a “bolt-on and forget it” accessory, it’s for fabrication jobs.
Key takeaways before you buy
It has a female 1/4" NPT thread, and it’s designed to be welded in, with a stepped design intended to make fabrication easier. The bung is made from mild steel and comes in a natural finish.
A couple of honest limitations to consider: because it’s a weld-on component, you’ll need the right welding capability and confidence to get a clean, leak-resistant weld. Also, the spec provided only calls out the NPT thread size and the outer diameter, it doesn’t mention any particular compatibility with specific sensors, adaptors, or hose ends, so you’ll still want to double-check that whatever you plan to screw into it is truly 1/4" NPT.
What you’ll notice during fabrication
The stepped design is the sort of detail that matters when you’re working under time pressure or in tight engine bay spaces. Over the long run, it can help you position the bung more confidently while you tack and finish the weld.
Imagine a typical home workshop scenario: you’ve marked the position on an intercooler pipe where you want a new connection, then you tack the bung in place, check alignment, and weld around the base. Once it’s cooled, you can then thread in your next component using the female 1/4 NPT thread. That workflow—weld first, then thread—fits exactly the “fabricate a port” use case.
Where it makes sense (and where it doesn’t)
It’s a good fit if you’re doing custom automotive fabrication and you specifically need a female 1/4 NPT threaded outlet, with the option to weld it onto steel or compatible metal surfaces. If your plan is fuel, tank, or similar plumbing work, this type of bung can be a sensible way to create a permanent connection point.
It might not be a great match if you want something truly plug-and-play. The whole value proposition here is welding in a bung, not using clamps or quick fittings. And if your project relies on a very specific component interface (for example, a particular aftermarket part with a non-standard thread or sealing method), you’ll want to verify that the connection method matches what you’re building.
Tech specs
- Name: AC PERFORMANCE Steel Female 1/4 NPT Weld On Bung
- Type: Weld on bung fitting
- Format: Female thread
- Capacity: pack of 2
- Thread size: 1/4" NPT
- Outer diameter: 22mm (0.9")
- Material: mild steel
- Colour: natural
Should you buy it?
It’s worth it when you’re comfortable with fabrication and you need a welded-in female 1/4 NPT threaded port for automotive-style plumbing such as fuel/tank-related work or custom pipe/mandifold projects. The pack of 2 is also helpful when you want symmetry or you’d rather not risk running short mid-job.
Better avoided if you’re looking for an installation that doesn’t involve welding, or if you’re not sure your downstream parts are actually intended for 1/4" NPT female threads. In that case, the fitting may solve one problem while creating another.
Mini FAQ
Is this a bolt-on fitting?
No—this is designed to be welded on (weldable bung), so installation requires welding work.
What thread type does it use?
It has a female 1/4 NPT thread.
What material is it made from?
It’s made from mild steel.
What does the stepped design do?
The stepped design is meant to make fabrication easier, mainly by helping with positioning during welding.
How many are included?
You get a pack of 2 weldable bungs.