Proto J5128 Crowfoot Wrench 7/8 in 3/8 in Drive 12-point

Product Description

The PROTO J5128 is a 7/8 inch crowfoot wrench built for 3/8 inch drive ratchets and extensions. It delivers 12-point engagement on hex fasteners in tight or offset locations where standard open-end or box wrenches cannot reach. The chrome-plated finish resists corrosion and stands up to shop environments. The head measures 1-11/64 inches in diameter and 31/64 inches thick, keeping the profile low enough to work in confined spaces. Overall length is 2-63/64 inches. At 0.16 pounds, it is light enough to carry in a pouch or add to a socket tray without bulk. Licensed tradespeople, mechanics, and industrial maintenance technicians are the primary users.

Crowfoot wrenches are used wherever a standard socket cannot seat over a fastener — fuel line fittings, hydraulic line adapters, sensor bungs, and structural bolts in confined assemblies are common applications. The J5128 fits into HVAC equipment service, plumbing rough-in, and mechanical piping work where 7/8 inch fittings appear on tubing, unions, or valve packing nuts. The 3/8 inch drive allows pairing with torque wrenches for controlled tightening, making it suitable for applications governed by published torque specifications.

Key Features

• 7/8 inch wrench size on a 3/8 inch square drive — pairs with standard ratchets, extensions, and torque wrenches
• 12-point design provides six engagement positions for easier placement in tight quarters
• Low-profile head at 31/64 inches thick for access in confined fastener locations
• Chrome-plated finish for corrosion resistance and easy cleaning
• Meets AS954E S3.8.1 standards
• Limited Lifetime Warranty from the manufacturer

Compatibility

Designed for use with standard 3/8 inch drive ratchets, extensions, and torque wrenches that accept crowfoot-style attachments.

Installation Notes

Crowfoot wrenches must be used at 0 degrees or 90 degrees offset from the drive to maintain accurate torque readings when paired with a torque wrench — any other angle introduces error. Always verify the drive connection is fully seated before applying load. Disengage all power, pressure, or fluid supply to the system before loosening or tightening fittings. Chrome hand tools should not be used with impact drivers.