NPT Male Coupler/Union, Straight

Two female ports staring at each other, and nothing in the drawer to marry them.

Filter housings, valves, and accessory blocks all love to arrive with female NPT ports, which is great until two of them need to connect. The Finish Line Factory NPT Male Coupler/Union, Straight is the double-male nipple that joins them, CNC machined from 6061 aluminum with a black anodized finish, in matched 1/8" through 1/2" NPT. Thread one end into each port and two loose components become one plumbed assembly. The unglamorous part every parts drawer should stock.

Benefits

• Two components mate into one solid, wiggle-free assembly
• Machined threads walk in straight, no chasing damaged cast threads with a file
• Center hex takes a real wrench, so installation torque goes where you aim it
• Compact joined stack instead of a hose looping between neighboring parts
• Spares on the shelf mean mid-build port surprises don't stall the weekend

Features

• CNC machined 6061 aluminum, black anodized
• Male NPT tapered thread on both ends
• Matched sizes: 1/8", 1/4", 3/8", 1/2" NPT
• Center wrench flats for controlled assembly
• Suits fuel, oil, coolant, and air service
• Single coupler per order in your selected size

The Details

A male union is two tapered joints sharing one body, and the assembly order matters more than it looks. Sealant goes on both thread sets, lead threads kept clean, and the union threads fully into the first component before the second component spins on, using the center hex to control which joint is actually turning. Because both ends are tapers, both stop where they bind, so a union works best joining components that can tolerate whatever final rotational position the threads settle into; anything needing exact clocking between the two parts is a job for a different fitting arrangement. Keep in mind that a rigid union also makes the two components move as one, so a heavy filter housing joined to a bracket-mounted valve should have its own support rather than hanging its full weight and vibration on the threads. Where the sizes need to change across the joint, pair a union with the FLF NPT Pipe Reducer or skip straight to a reducer alone. Anodized aluminum keeps the assembly light and corrosion-free around fuel and coolant.

Kit Includes

• 1x NPT Male Coupler/Union, Straight (size per your selection)

Applications

• NPT sizes: 1/8", 1/4", 3/8", 1/2", male both ends, same size through
• Common uses: joining fuel filter housings to fittings or valves, connecting gauge adapters and manifolds, closing the gap between accessory blocks, extending a female port outward for wrench access
• Accepts any female NPT port or fitting in the matching size, including the female side of FLF adapters