Proto J4910MHFL Flare Nut Crowfoot Wrench 3/4 Inch

Product Description

The PROTO J4910MHFL is a 3/4 inch flare nut crowfoot wrench designed for use with a 1/4 inch drive torque wrench or ratchet extension. The enclosed 6-point head grips hex flare nuts and fittings on all sides, reducing the risk of rounding during tightening or loosening. With a head diameter of 0.77 inches and a head thickness of 0.25 inches, this tool reaches fasteners in tight spaces where a standard open-end or box-end wrench cannot. The chrome-plated finish resists corrosion and allows for easy cleaning after use in oily or refrigerant-exposed environments. Licensed plumbers, HVAC technicians, and refrigeration mechanics keep this wrench in rotation for work on flare fittings, brake lines, and fuel lines.

The J4910MHFL is sized for 3/4 inch flare nuts and compatible fittings commonly found in residential and light commercial HVAC and refrigeration systems, as well as plumbing and automotive brake line service. Its overall length of 1.9375 inches makes it practical for confined engine bays, mechanical rooms, and equipment closets where standard wrenches cannot develop adequate torque. Technicians pair this crowfoot with a calibrated torque wrench when flare joint specifications must be met precisely.

Key Features

• 3/4 inch wrench size for standard flare nut and hex fitting applications
• 6-point head geometry reduces fastener rounding compared to 12-point designs
• 0.25 inch head thickness allows access in shallow clearance situations
• Chrome-plated finish resists corrosion and simplifies cleanup
• Meets ASME B107.21 and Federal Specification GGG-C-1507b
• Covered by a Limited Lifetime Warranty

Compatibility

Designed for use with 1/4 inch drive torque wrenches and ratchet extensions on 3/4 inch flare nuts and fittings. Suitable for HVAC, refrigeration, plumbing, and related trade applications requiring a crowfoot-style wrench in the 3/4 inch size.

Installation Notes

This tool is installed by HVAC technicians, refrigeration mechanics, and licensed plumbers as part of standard hand tool procedures. Always ensure the crowfoot is fully seated on the fastener before applying torque, and confirm drive direction before use on flare fittings to avoid joint damage. Follow applicable codes and manufacturer fitting specifications when torquing refrigerant or gas line connections. Clean the wrench after each use to maintain the chrome finish and prevent contamination of system components.