Brasscraft 66-6-6X Compression Adapter 3/8 in Brass

Product Description

The BRASSCRAFT 66-6-6X is a 66 Series brass compression adapter designed to connect 3/8 inch compression tubing to a female NPT threaded fitting. This type of adapter is a standard fitting used in plumbing, HVAC, and gas supply applications where a transition between compression and NPT threads is required. The all-brass construction provides corrosion resistance and durability under normal service conditions. Licensed plumbers and HVAC technicians install this fitting during new construction and retrofit work where fuel gas, water, or other compatible fluid lines require a secure, leak-free transition joint.

This adapter is suited for residential and light commercial plumbing and mechanical installations. It is commonly used at appliance connections, shutoff valves, and supply line terminations where a 3/8 inch compression line must mate with a female NPT port. The 66 Series designation indicates the fitting family within the BRASSCRAFT product line, which is widely stocked for standard plumbing and gas piping work.

Key Features

• 3/8 inch compression inlet connects to female NPT outlet for a reliable transition joint
• Brass construction resists corrosion in water and gas service environments
• Compression x FNPT configuration eliminates the need for soldering at the compression end
• Part of the established 66 Series fitting family for consistent sizing and thread standards

Compatibility

Designed as an OEM-style replacement and standard-use fitting for residential and light commercial plumbing or gas supply lines requiring a 3/8 inch compression to female NPT transition.

Installation Notes

Installation should be performed by a licensed plumber or qualified HVAC technician in accordance with applicable local codes and the International Plumbing Code or International Fuel Gas Code. Shut off the water or gas supply and depressurize the line before beginning work. Hand-tighten the compression nut first, then snug with a wrench — do not overtighten, as this can crack the ferrule or distort the fitting body. Apply thread sealant or PTFE tape to the NPT threads as required by the applicable code and fitting manufacturer guidance.

Technical Specifications

• Series: 66 Series
• Connection Type: Compression x FNPT
• Size: 3/8 inch
• Material: Brass

Standard Information

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