Proto J5428SPL Spline Socket 1/2 in Drive 28 Spline

Product Description

The PROTO J5428SPL is a 12-point spline socket designed for heavy-duty fastener removal and installation in professional trade and industrial applications. Built on a 1/2 inch drive, it accepts 28-spline fasteners with a 7/8 inch hex size. The 12-point internal geometry increases contact points, reducing fastener rounding during high-torque operations. This socket is manufactured to meet Federal Spec GGG-W-641e and ANSI Spec B107.1, confirming it meets established dimensional and performance standards for hand tools. It weighs 0.24 pounds and is sold individually. Mechanics, millwrights, pipefitters, and general maintenance technicians who work with spline-drive fasteners will find this socket a direct-fit, code-compliant solution.

The J5428SPL is suited for automotive, industrial maintenance, and mechanical assembly environments where spline-drive fasteners are specified. Spline sockets are commonly used on heavy equipment, fleet vehicles, and industrial machinery where standard hex or 12-point sockets are not compatible with the fastener head. The 1/2 inch drive makes this socket compatible with standard 1/2 inch drive ratchets, breaker bars, torque wrenches, and impact tools designed for that drive size. It is packaged and sold as a single unit.

Key Features

• 1/2 inch drive accepts standard ratchets, breaker bars, and torque wrenches
• 28-spline configuration fits spline-drive fasteners requiring a 7/8 inch hex size
• 12-point internal geometry increases engagement and reduces fastener rounding
• Meets Federal Spec GGG-W-641e and ANSI Spec B107.1 for dimensional and performance compliance
• Lightweight at 0.24 pounds for a 1/2 inch drive socket
• Sold individually with a minimum order quantity of 1

Compatibility

Designed for use with 1/2 inch drive ratchets, breaker bars, torque wrenches, and compatible impact tools. Fits 28-spline fasteners with a 7/8 inch hex dimension as found on heavy equipment, fleet vehicles, and industrial machinery.

Installation Notes

This socket is installed and used by mechanics, millwrights, and maintenance technicians working with spline-drive fastener applications. Before use, confirm the drive tool and socket are properly seated and rated for the torque being applied. Inspect the socket for wear or cracks before each use, and replace if deformation is observed. Do not use damaged sockets or attempt to extend drive handles with makeshift adapters beyond the rated capacity of the tool.