Proto J3700A Flare Nut Wrench Set 7 Piece Inch

Product Description

The PROTO J3700A is a 7-piece flare nut wrench set designed for working on tubing fittings and flare connections found in HVAC, refrigeration, and plumbing systems. Each wrench features a 6-point design that grips hex fasteners on all flat faces, reducing the risk of rounding soft brass or steel fittings. The satin finish reduces glare in the field and resists corrosion. The set covers seven fractional inch sizes and ships in a tool roll for organized storage and transport. HVAC technicians and plumbers reach for these wrenches when tightening or loosening flare nuts on refrigerant lines, gas connections, and hydraulic fittings where open-end wrenches would slip or damage the fitting.

Flare nut wrenches are a standard tool for residential and light commercial HVAC and refrigeration work, particularly when connecting or disconnecting copper tubing at service valves, flare fittings, and compression unions. The enclosed-end design wraps around the fitting for maximum contact, which is especially valuable on soft brass refrigerant fittings that deform easily. This set is suited for bench use or field service kits where a full range of fractional inch sizes is needed without carrying individual wrenches.

Key Features

• 7-piece set covers 3/8 in, 7/16 in, 1/2 in, 9/16 in, 5/8 in, 11/16 in, and 3/4 in sizes
• 6-point wrench opening maximizes contact on hex fittings and minimizes rounding
• Satin finish reduces surface glare and provides corrosion resistance
• Enclosed flare nut profile keeps the wrench seated on tube fittings during torque application
• Includes tool roll for organized storage and easy transport to the job site
• Inch measurement system for use with standard fractional tubing and fittings

Compatibility

Designed for use with standard fractional inch flare nut and tube fitting applications common in HVAC, refrigeration, and plumbing service work.

Installation Notes

Flare nut wrenches are used by HVAC technicians, refrigeration mechanics, and plumbers. Before working on refrigerant lines, recover refrigerant per EPA Section 608 requirements and depressurize the system. Before working on gas or water lines, shut off the supply valve and verify pressure is relieved. Use the correct size wrench for each fitting to avoid deforming flare seats or fittings.