Proto J3751T Combination Flare Nut Wrench 3/8 Inch

Product Description

The PROTO J3751T is a double-end combination flare nut wrench designed for gripping and turning flare fittings on refrigerant lines, fuel lines, and hydraulic connections. Built from steel with a satin finish, it features a 12-point head profile that allows engagement in tight spaces where a standard open-end wrench cannot seat properly. The 15-degree head offset angle provides clearance over obstructions common in line work. With an overall length of 5-11/16 inches and a 3/8 inch wrench size, it is suited for close-quarters work on small-diameter fittings. HVAC technicians, refrigeration mechanics, and plumbers reach for this style of tool when torquing or breaking loose flare connections without rounding the fitting hex.

The J3751T is used wherever tube fittings require a dedicated flare nut wrench rather than an open-end or adjustable tool. Typical applications include refrigerant line sets at indoor and outdoor unit connections, fuel delivery lines in commercial kitchen or rooftop equipment, brake and hydraulic lines in light industrial settings, and gas appliance supply connections. The 3/8 inch size targets the smaller fittings found on 1/4 inch and 5/16 inch OD tubing common in HVAC and light plumbing work.

Key Features

• Double-end head configuration provides two engagement points in a single tool
• 12-point flare nut head design reduces slippage on soft brass and aluminum fittings
• 15-degree head offset angle clears obstructions in confined installation areas
• Satin finish reduces glare and resists surface corrosion in field conditions
• Steel construction for durability under standard hand-torque loads on tube fittings
• Compact 5-11/16 inch overall length suited for tight access on line sets and appliance connections

Compatibility

Designed as an OEM-style hand tool for use on 3/8 inch flare nut fittings across residential and light commercial HVAC, plumbing, and fuel line applications.

Installation Notes

Flare nut wrenches should be used in place of open-end wrenches whenever possible to reduce the risk of rounding flare fitting hexes. Before servicing refrigerant or fuel line connections, recover or isolate the system per applicable codes and confirm pressure has been relieved. Always hand-seat fittings before applying wrench torque. This tool is intended for hand-torque use only and should not be used with cheater bars or impact drivers.