Ailbiuko 106PCS Brass Pipe Fittings Assortment Kit NPT Extension Adapter,Reducer Bushing,Hex Nipple,Close Nipple,Reducing Hex Coupling,Hex Head Plugs,Hex head Cap,Socket Plug Kit

Why I wanted this kit

I spend an unreasonable amount of time hunting for one-off brass fittings during projects—plumbing in a small compressor manifold, tying in gauges on a test rig, or adapting fuel and coolant lines during prototyping. The Ailbiuko 106-piece brass NPT assortment promised to cut those interruptions. It’s a dense kit: male/female tapered fittings across adapters, nipples, bushings, plugs, caps, couplings, plus a roll of PTFE tape. I’ve now put a couple dozen pieces to work across air and light oil service, and I have a clear sense of where this kit shines and where it comes up short.

Build quality and machining

The fittings are made from CA360 forged brass. In hand, they feel substantial with crisp hex faces and clean chamfers. Threads are consistently well formed—no burrs or torn crests—and I didn’t encounter any cross‑threading or gritty starts when mating to valves, regulators, or pipe. The flats take a wrench well without rounding, and the hex head plugs and caps seat confidently.

Brass is the right choice for most shop and instrumentation tasks: good corrosion resistance, easy to seal, and kinder to mating components than stainless. CA360 also machines cleanly, which shows up here in the thread quality. One note: CA360 is not a lead‑free alloy. I would not use these on potable water systems unless you’ve verified a lead‑free rating elsewhere; this kit is really aimed at air, oil, inert gas, and general instrumentation.

Thread fit and sealing

These are NPT (tapered) threads, which rely on interference as they tighten. The kit includes a roll of PTFE tape that’s serviceable—thin, but adequate for air and many oils. For critical or oily systems, I had better results with a higher‑density tape or a non‑hardening pipe dope. On a 120 psi shop air manifold, everything sealed leak‑free with two to three wraps of tape and proper torque. I pressure‑soaked a section for 24 hours and saw no bubbles in a soapy solution.

A simple reminder for anyone newer to NPT: the nominal size does not match a ruler measurement of the outside diameter. That’s normal. The included labeling in the case helps, but it’s worth double‑checking sizes before you commit thread sealant.

What’s actually in the box

The assortment leans on the basics you need most often:

• Hex nipples (standard and close) for straight unions
• Hex bushings for stepping down
• Female couplings and reducing couplings
• Hex head plugs and socket plugs
• Female hex caps
• Male-to-female adapters

The temperature rating is listed at -65°F to +250°F, which covers typical shop air, instrumentation, and many hydrocarbon duties. There’s no explicit pressure rating provided; I treated these as general-purpose brass fittings and kept them in low to moderate pressure roles. For high-pressure hydraulics or critical gases, I’d want manufacturer data before trusting them.

Assortment balance

Overall selection is generous, but the ratios matter. I ended up using more bushings and close nipples than the kit provides. By contrast, the number of plugs and caps is high. If you build manifolds, test blanks, or like to plug ports while you configure a system, you’ll appreciate the extras. If you do more adapting than capping, you may wish there were more close nipples and reducers.

There’s also a labeling quirk in the “reducer adapter” section: some pieces are same‑size male‑to‑female extensions. They’re not reducers in the strict sense, but they’re handy as standoffs. I used one to bring a valve body out from a manifold to gain wrench clearance. Still, calling them “reducers” is misleading, and first‑time users could be confused.

Notably absent are elbows and tees. This kit is straight-line only, so plan on supplementing with angled fittings if your layout requires turns.

In use: air, oil, and instrumentation

• Compressed air manifold: I built a six-port block with a pressure regulator, two gauges, and quick-connect couplers. The hex nipples and bushings covered everything I needed. After taping and torquing, the assembly held 120 psi overnight without drop.
• Light oil loop: For a gear pump test, I threaded in two BSPP-to-NPT adapters I already owned and finished the run with bushings and caps from this kit. No seepage after cycling to 150°F oil temperature; the 250°F rating gives me comfortable headroom here.
• Instrumentation stubs: Socket plugs and hex caps made it easy to blank ports while I swapped sensors. The small hex flats are convenient in tight panels.

I wouldn’t use this kit for steam, high-temperature glycol circuits above 250°F, or oxygen service without appropriate cleaning and ratings. For oxygen in particular, use components specifically prepared and labeled for O2 duty.

Ergonomics and organization

The case is compact with individual compartments that keep sizes separated. The lid’s fit is tight enough that parts don’t migrate between bins if you carry it upright. The inventory card makes restocking and quick size checks painless. I’ve tossed the case into a job bag a few times; the latch didn’t pop and the hinges feel sturdier than typical budget assortments.

Durability and corrosion

Brass holds up well in indoor and many outdoor scenarios. If you’re mating to stainless or aluminum in marine or humid environments, be mindful of galvanic pairing and consider anti-seize plus thoughtful material choices. For refrigeration or salt-laden atmospheres, I’d still trust these, but I would inspect periodically and avoid long-term dissimilar metal stacks without isolation.

Quibbles and cautions

• Ratios: Too many caps and plugs relative to close nipples and reducers. I ran short on close nipples after a couple of builds.
• Ambiguous labeling: “Reducer adapters” includes same-size extensions. They’re useful, but the name is off.
• No elbows or tees: You’ll need a supplemental assortment for directional changes.
• Potable water uncertainty: No lead-free claim. I’m treating this as not for drinking water.
• Pressure rating not stated: Fine for shop air and light oil, but I’d avoid high-pressure systems without documentation.

None of these are deal-breakers, but they’re worth knowing so you can plan around them.

Tips for best results

• Use the right sealant: PTFE tape works for most air and many oils; paste sealant is my preference for fuel and hot oil.
• Don’t over-torque: NPT seals by taper; finger-tight plus 1–2 wrench turns is a good starting point. Overdoing it can crack female fittings.
• Chase paint or debris: If you’re threading into a painted manifold or a casting, clean the female threads first. The clean threads in this kit deserve a clean mate.
• Keep plugs handy: The abundance of plugs is actually useful when pressure-testing sections before final assembly.

Value

Buying brass fittings one at a time is expensive and time‑consuming. The per‑piece cost in this kit undercuts hardware store prices dramatically, and the machining and finish are on par with the name-brand fittings I usually grab. Even with the imperfect mix of parts, the convenience and price make it an easy keep in the shop. I’d happily buy the kit again and top it up with a separate pack of close nipples and elbows.

Bottom line

This 106-piece brass NPT assortment earns a permanent spot on my bench. The machining is clean, the threads are consistent, and sealing has been straightforward across air and light oil applications. The assortment skews toward plugs and caps, and the labeling could be clearer, but the overall utility, organization, and value are hard to argue with.

Recommendation: I recommend this kit to anyone who regularly works with NPT fittings for air, oil, and general instrumentation. It won’t replace specialty or high-pressure components, and you’ll still want a small stash of elbows and tees, but as a first‑reach organizer of quality straight fittings at a reasonable cost, it’s excellent.