Proto J3764T Open End Flare Nut Wrench 3/8 X 7/16 in

Product Description

The PROTO J3764T is a double-end open end flare nut wrench designed for use on flare fittings in refrigeration, HVAC, and plumbing applications. It spans 3/8 and 7/16 inch fitting sizes and features a 12-point contact design that grips hex and flare nuts securely without rounding. The overall length is 6.25 inches, and the tool is forged steel with a satin finish that resists corrosion and reduces glare. Weighing 0.18 pounds, it is a compact, single-tool solution for techs working on refrigerant line connections, fuel lines, and compression fittings in confined spaces.

This wrench is suited for HVAC technicians, refrigeration mechanics, and plumbers who regularly work with flare fittings on copper tubing. The open-end flare nut design allows the wrench to slip over tubing before seating on the fitting, which is essential when the nut cannot be accessed from the end of a line. It is equally at home on residential split systems, light commercial refrigeration equipment, and plumbing rough-in where compression or flare connections are present.

Key Features

• Double-end head fits both 3/8 inch and 7/16 inch flare nuts in a single tool
• 12-point contact geometry reduces fastener rounding under torque
• 6.25 inch overall length provides leverage in tight service spaces
• Forged steel construction for durability under repeated use
• Satin finish resists corrosion and minimizes surface glare
• Lightweight at 0.18 pounds, suitable for belt pouches and tool rolls

Compatibility

Designed as an OEM-style hand tool replacement suitable for use on standard SAE flare nut fittings found in residential and light commercial HVAC, refrigeration, and plumbing systems.

Installation Notes

This wrench is used by HVAC technicians, refrigeration mechanics, and licensed plumbers. Always recover refrigerant and isolate the system before loosening flare connections on refrigerant lines. On gas or fuel lines, shut off supply valves and verify pressure is relieved before breaking any fitting. Use the correct size wrench for the fitting to avoid rounding the nut; never substitute an adjustable wrench on flare fittings under high torque.