Proto J5421M 21mm 12-point 1/2 Drive Hand Socket

Product Description

The PROTO J5421M is a 21 mm, 12-point hand socket designed for professional-grade fastener work. Built from alloy steel with a chrome-plated finish, it seats on a 1/2 inch drive and measures 1.5 inches in overall length, placing it in the standard-length category. The 12-point configuration engages hex fasteners from more entry angles than a 6-point design, which speeds work in tight or awkward positions. Mechanics, millwrights, maintenance techs, and industrial service professionals use this socket where durability and precise fit matter. It meets AS4984A and ASME B107.110-2012 standards.

This socket is suited for general mechanical and maintenance applications requiring a 21 mm fastener engagement with a 1/2 inch drive ratchet or breaker bar. Typical use cases include automotive service, heavy equipment maintenance, and industrial assembly where a standard-length chrome socket handles everyday torque demands without specialized extension requirements. The chrome finish resists corrosion in shop environments and allows for easy cleaning.

Key Features

• 21 mm socket size with 12-point configuration for broad fastener engagement angles
• 1/2 inch drive compatible with standard ratchets, breaker bars, and torque wrenches
• Alloy steel construction for strength under high-torque applications
• Chrome-plated finish for corrosion resistance and cleanability
• Standard length at 1.5 inches overall for everyday service tasks
• Meets AS4984A and ASME B107.110-2012 standards

Compatibility

Designed for use with 1/2 inch drive ratchets, breaker bars, and torque wrenches in professional mechanical and maintenance service applications.

Installation Notes

Licensed mechanics and maintenance technicians install and use hand sockets as part of routine fastener service. Always ensure the socket is fully seated on the fastener before applying torque to prevent rounding. Inspect the socket for cracks or deformation before each use and remove from service if damage is found. This socket is not tether capable and should not be used in overhead or elevated work where dropped-tool hazards exist.