Guest 3/8 M Conn

The John Guest 3/8" Male Connector from Reliance Worldwide Corporation transitions 3/8" push-fit tubing to a 3/8" male iron pipe thread, providing a fast, secure way to connect tubing to threaded ports on filters, valves, and manifolds in water treatment systems. Because both sides stay at 3/8", it maintains full line size without any reduction, supporting good flow through filter housings and distribution plumbing.

Male connectors are among the most-used fittings in any treatment build because so many components present tapped, threaded inlets and outlets that must mate with flexible tubing. This connector handles that everyday transition cleanly: the push-in collet grips and seals the tube automatically, while the threaded end screws into the component port, all without stacked adapters that add height and leak points.

Key Features

• Connection: Tube x MIPT, both 3/8"
• Straight male connector for tube-to-thread transitions
• Polypropylene construction resists corrosion and scale
• Push-fit tube end seats instantly without tools
• Maintains full 3/8" line size for good flow
• Demountable for clean, repeatable servicing

To install, wrap the male thread with PTFE tape and hand-tighten it into the port, snugging it just past finger-tight to avoid cross-threading the plastic. Then cut your 3/8" tube square and free of burrs, push it fully into the collet until it bottoms out, and confirm the connection with a light pull. The internal O-ring forms a watertight seal automatically. The corrosion-resistant polypropylene body stands up to years of contact with treated water without scaling or rusting, unlike some metal fittings. To take the line apart later, depress the collet and the tube slides free without damage, ready to reconnect. For dependable, full-flow tube-to-thread joins in residential filtration and reverse osmosis plumbing, this John Guest male connector is a reliable, reusable choice.

Keeping a supply of these full-size male connectors on hand makes hooking tubing to threaded components effortless across an entire build. As part of the John Guest range, it works seamlessly with the unions, tees, elbows, and valves that share the same collet system, letting you assemble a complete filtration or RO layout from interchangeable push-fit parts that all behave consistently and come apart the same simple way.