Brasscraft 66-6-8X Tube Reducing Adapter 3/8x1/2 Compression Fnpt

Product Description

The BRASSCRAFT 66-6-8X is a tube reducing adapter designed to connect tubing and threaded pipe fittings of two different sizes in a single, compact fitting. It transitions from a 3/8-inch compression connection on one end to a 1/2-inch female national pipe thread (FNPT) on the other, making it a practical solution for reducing or stepping down line sizes in tight plumbing assemblies. Constructed from solid brass, this adapter offers corrosion resistance and reliable sealing performance under normal service conditions. It is suited for use by licensed plumbers and experienced trade professionals working on supply line connections, appliance hookups, and distribution piping.

This adapter sees typical use in residential and light commercial plumbing applications where a compression tube must terminate at a threaded port of a different size. Common install scenarios include water supply connections at fixtures, valves, or appliances where tubing size does not match the port size on the receiving component. The compression end accepts standard tubing, while the FNPT end threads directly into compatible female-threaded fittings or valve bodies.

Key Features

• Reduces from 3/8-inch compression to 1/2-inch FNPT in a single fitting
• Solid brass construction for corrosion resistance and long service life
• Compression end provides a secure, tool-assisted seal without soldering
• FNPT end threads directly into standard female pipe thread ports
• Domestic manufacture

Compatibility

Designed as an OEM-style replacement or service fitting for residential and light commercial plumbing systems requiring a 3/8-inch compression to 1/2-inch FNPT transition.

Installation Notes

Installation is performed by a licensed plumber. Shut off the water supply and relieve line pressure before disassembling any existing fittings. The compression end requires a ferrule and compression nut; hand-tighten first, then snug with a wrench — do not overtighten, as over-compression can deform the ferrule and cause leaks. Apply thread sealant or PTFE tape to the FNPT threads per local plumbing code requirements before making the threaded connection.

Technical Specifications

• Inlet Size: 3/8 inches (compression)
• Outlet Size: 1/2 inches (FNPT)
• Connection Type: Compression x FNPT
• Material: Brass
• Origin: Domestic

Standard Information

• Brand: BRASSCRAFT
• Manufacturer Part Number: 66-6-8X