Proto J5021M Deep Hand Socket 21mm 12-point 3/8 Drive

Product Description

The PROTO J5021M is a deep hand socket designed for professional-grade fastener work where standard-depth sockets cannot reach. Built from alloy steel with a chrome-plated finish, this 21 mm socket features a 3/8 inch drive and a 12-point configuration, allowing engagement from multiple angles on hex fasteners. At 2.75 inches in overall length, the deep profile provides the clearance needed for recessed bolts, studs, and long fastener threads. It meets ANSI B107.5 standards and carries a lifetime warranty. Mechanics, millwrights, and general maintenance technicians rely on this socket for under-hood, chassis, and industrial fastener applications.

The J5021M is suited for residential and commercial maintenance, automotive service, and light industrial environments where a 3/8 inch drive torque wrench or ratchet is the preferred tool. The deep length is particularly useful on wheel hardware, suspension components, and any installation where a fastener sits below a surface or inside a recessed bore. Its 12-point design works on both standard hex and double-hex fasteners, giving the technician more positioning options in tight quarters.

Key Features

• 21 mm socket size accommodates common metric fasteners found in automotive and industrial applications
• 12-point design allows 30-degree indexing increments for improved access in confined spaces
• Deep length of 2.75 inches reaches recessed bolts and long-thread fasteners
• Alloy steel construction provides strength and resistance to rounding under torque
• Chrome-plated finish resists corrosion and simplifies cleaning in shop environments
• Meets ANSI B107.5 standards for hand socket performance and dimensions
• Lifetime warranty backed by the manufacturer

Compatibility

Designed for use with any 3/8 inch drive ratchet, torque wrench, or extension bar conforming to standard 3/8 inch square drive dimensions.

Installation Notes

Installation and removal of fasteners with this socket should be performed by a qualified mechanic or maintenance technician using a calibrated torque wrench where fastener torque specifications apply. Ensure the drive tool is fully seated in the socket before applying torque to prevent slippage or 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 elevated or overhead work areas where drop hazards exist.