Brass Compression Straight Coupling Connector – Flared Fittings for Copper Pipe

Measure your copper pipe's outer diameter (OD) with calipers — common sizes are 6mm (≈1/4"), 8mm (≈5/16"), 10mm (≈3/8"), 12mm (≈1/2"), and so on. Then match the thread size to your fitting port: NPT sizes (1/8", 1/4", 3/8", 1/2") are standard in US residential plumbing, while metric threads (M14×1.5, M16×1.5, M18×1.5, M20×1.5) are typically found on European equipment or automotive cooling/fuel systems. When in doubt, check the thread pitch with a thread gauge before ordering.

Brass compression fittings generally handle working pressures up to 200–300 PSI for water and compressed air applications, though the exact rating depends on pipe OD, wall thickness, and installation quality. For high-pressure hydraulic or gas lines, please contact us to confirm suitability before ordering.

Brass is naturally corrosion-resistant and performs well in most indoor and sheltered outdoor environments. It is not recommended for direct burial or prolonged exposure to salt spray without additional protection. For fully outdoor or marine applications, stainless steel fittings are generally a better choice.

These compression couplings are designed primarily for copper pipe and are generally compatible with soft copper, aluminum, and some plastic tubing of the matching OD. They are not recommended for hard stainless steel or rigid iron pipe. Always verify the pipe OD and wall thickness match the fitting's rated range before installation.

No — variants labeled "Without nuts" include only the coupling body and ferrule (olive). You will need to source compatible compression nuts separately. Standard variants (6mm through 16mm pipe OD options) include the full fitting assembly with nuts included.

For a single pipe joint, 1 piece is sufficient. We offer packs of 1, 3, 5, and 10 pieces — buying in larger quantities typically reduces the per-unit cost and ensures you have spares on hand for future repairs or multi-joint installations.

For the threaded port connection, applying 2–3 wraps of PTFE (Teflon) tape or a compatible thread sealant compound is generally recommended to ensure a leak-free seal, especially on NPT tapered threads. The compression side (pipe OD) seals mechanically via the ferrule and does not require tape.