Proto J4910MCF Open End Crowfoot Wrench Metric

Product Description

The PROTO J4910MCF is a metric open end crowfoot wrench designed for use with standard 1/4 inch drive torque wrenches and extension bars. It features a chrome-plated finish for corrosion resistance and durability in shop and field conditions. The head measures 0.95 inches in diameter with a 0.25 inch head thickness, and the overall tool length is 1.17 inches. This wrench is built to ASME B107.21 standards and meets Federal Specification GGG-C-1507b, making it appropriate for professional and government-contract work. Licensed trades including mechanics and maintenance technicians use this type of crowfoot fitting to access fasteners in tight spaces where a standard socket or box wrench cannot seat.

Open end crowfoot wrenches like the J4910MCF are used in automotive, industrial, and mechanical maintenance applications where a straight line of access to a fastener is not available. The low-profile head and slim thickness allow it to fit into confined spaces around plumbing fittings, fuel lines, brake lines, and mechanical assemblies. The metric sizing makes it suitable for equipment manufactured to metric specifications. Technicians pair this crowfoot with a torque wrench extension or ratchet drive for precise fastener seating in professional service environments.

Key Features

• Open end crowfoot design fits 1/4 inch drive torque wrenches and ratchets
• Chrome-plated finish resists corrosion and simplifies cleaning
• Head diameter of 0.95 inches with 0.25 inch head thickness for low-profile access
• Overall length of 1.17 inches for compact fitment in tight spaces
• Meets ASME B107.21 and Federal Specification GGG-C-1507b
• Limited Lifetime Warranty from the manufacturer

Compatibility

Designed for use with standard 1/4 inch drive torque wrenches, ratchets, and extension bars in metric fastener applications.

Installation Notes

This crowfoot wrench is installed by licensed mechanics and maintenance technicians as a drive accessory, not a standalone hand tool. Before use, confirm the drive size of the crowfoot matches the torque wrench or ratchet being used. When applying torque through a crowfoot at an angle offset from the drive axis, consult the torque wrench manufacturer guidance on correction factors. Do not use with impact drivers, as the chrome finish and open end design are not rated for impact loads.