Proto J5210S 5/16 Inch 8-point Hand Socket 3/8 Drive

Product Description

The PROTO J5210S is an 8-point hand socket sized for 5/16 inch square nuts, built on a 3/8 inch drive. Machined from alloy steel and finished in chrome, this standard-length socket is designed for professional hand-tool use in industrial maintenance, mechanical assembly, and similar trade applications. It meets ASME B107.1 standards, which sets dimensional and performance requirements for hand sockets. The 8-point geometry is specifically intended for driving square nuts, making it a purpose-built tool where a standard 6-point or 12-point socket would slip or fail to seat properly. Overall length is 1-5/64 inches.

This socket is used wherever square nuts are encountered in mechanical, industrial, or maintenance work. Typical applications include structural fasteners, older mechanical equipment, utility hardware, and specialty assemblies that rely on square-nut fastening. It is well-suited for assembly-line technicians, maintenance mechanics, and field service professionals who need a reliable, standards-compliant socket for square fastener work. The chrome finish provides corrosion resistance for general shop and field use.

Key Features

• 8-point socket geometry designed specifically for driving square nuts
• 3/8 inch drive compatible with standard ratchets, extensions, and torque wrenches
• Alloy steel construction meets ASME B107.1 dimensional and performance standards
• Chrome plating provides corrosion resistance for shop and field environments
• Standard length at 1-5/64 inches overall for general-access fastener work
• Not tether-capable — standard configuration without lanyard attachment point

Compatibility

Designed as an OEM-style replacement or direct-use socket for 3/8 inch drive hand tool sets requiring an 8-point, 5/16 inch square-nut socket.

Installation Notes

Install and remove fasteners with the drive fully seated in the socket to prevent rounding. Power down or de-energize any equipment before accessing fasteners in electrical or mechanical enclosures. Use a calibrated torque wrench when fastener specifications require controlled preload. Inspect the socket for cracks or chrome flaking before each use and remove from service if damage is found.