Threaded Fittings

Threaded Fittings for Australian Plumbing and Industrial Pipework

Threaded fittings are the elbows, tees, couplings, reducers, and adapters that connect pipe runs in plumbing, hydraulic, pneumatic, and process systems. The threaded connection — typically BSPT (taper) or BSPP (parallel) for Australian work — provides a leak-tight joint that's serviceable for disassembly and reassembly. For Australian plumbers, fitters, and pipework contractors, the right fitting matched to thread standard, material, and pressure rating is essential. AIMS Industrial supplies threaded fittings across the materials and standards Australian customers actually use.

The fitting types we stock

• Elbows (90° and 45°) — for direction changes in pipework runs
• Tees — for branching from main runs
• Couplings (joiners) — for joining two pipes of the same size
• Reducers and reducing couplings — for transitioning between pipe sizes
• Caps and plugs — for sealing pipe ends
• Crosses — for four-way junctions
• Bushes (reducing bushes) — for reducing fitting size in tapped holes
• Hex nipples and barrel nipples — for connecting fittings end-to-end
• Unions — for connections that need to be disconnectable for service
• Sockets and adapters — for transitioning between thread standards (BSP to NPT, etc.)

Materials and applications

• Galvanised steel (malleable iron) — the everyday choice for water service and general plumbing
• Black malleable iron — for gas service and applications where galvanising isn't required
• Brass — for instrumentation, decorative, and corrosion-sensitive applications
• Stainless steel 316 — for marine, food-grade, and chemical-resistant applications
• Forged carbon steel — for higher-pressure industrial pipework
• Hydraulic-rated steel — for hydraulic system fittings rated to specific pressures

Thread standards

• BSPT (British Standard Pipe Taper) — taper thread that seals as it tightens; the most common Australian pipe thread for water and gas
• BSPP (British Standard Pipe Parallel, also called G-thread) — parallel thread that seals with O-rings or sealing washers; common in hydraulic and pneumatic equipment
• NPT (American National Pipe Taper) — US-spec taper threads found in imported equipment and US-standard pipework
• Metric — for some specialty fittings and European-spec equipment

BSPT, BSPP, and NPT are not interchangeable — confirm the standard before sourcing. Mixing thread standards causes leaks regardless of how tight the joint is made.

Sizing

Threaded fittings are sized by nominal pipe size (NPS) — a 1/2 inch fitting fits 1/2 inch nominal pipe. Common sizes include 1/8, 1/4, 3/8, 1/2, 3/4, 1 inch, 1-1/4, 1-1/2, 2 inch, with larger sizes for industrial pipework. The actual outside diameter of the pipe is larger than the nominal size — 1/2 inch nominal pipe has approximately 21mm OD on the pipe itself.

Where threaded fittings earn their place

• Plumbing — domestic and commercial water service
• Gas service — domestic gas and industrial gas distribution (codes specify materials and ratings)
• Hydraulic and pneumatic systems — industrial fluid power applications
• Compressed air distribution — workshop air systems
• Process pipework — process water, steam, and specific chemical service
• Fire main and sprinkler systems — to AS 2118 specification
• Instrumentation pipework — small-bore instrumentation lines using brass and stainless fittings

Sealing — match to service

Threaded fittings require thread sealant for leak-tight assembly. Common sealants:

• PTFE thread tape — the everyday plumbing standard for water service
• Pipe joint compound (paste) — gas-approved paste for gas service
• Anaerobic thread sealants — Loctite 567/577 for permanent industrial joints

See our thread sealants and pipe sealants ranges for the matching products. Don't over-tighten threaded fittings — strips threads, distorts the fitting, and creates more leak paths than it seals.

Brands and sourcing at AIMS

Threaded fittings are stocked from quality manufacturers covering galvanised malleable iron, black malleable iron, brass, and stainless steel ranges. For specialty fittings, large sizes, or high-pressure-rated forged fittings, sourcing through our distribution channels covers most options.

Companion ranges at AIMS

Threaded fittings sit alongside our broader pipework range — see steel fittings, pipes, tubes and fittings, pipe sealants, and thread sealants for the related products.

Need help speccing threaded fittings for a specific service or pressure? contact our team — we'll match by thread standard, material, and pressure rating.