Proto J5216SPL Spline Socket 3/8 in Drive 16 Spline

Product Description

The PROTO J5216SPL is a spline socket designed for professional hand-tool use in mechanical, automotive, and industrial service applications. It accepts a 3/8 inch drive and fits 16-spline fasteners with a 1/2 inch hex size. The 12-point internal geometry provides full engagement on spline-type fasteners, reducing the risk of fastener rounding under torque. At 0.07 pounds, it is lightweight without sacrificing the durability expected from a trade-grade hand tool. Licensed technicians, mechanics, and maintenance professionals reach for this socket when working on equipment that uses spline-head fasteners in tight or torque-critical locations.

This socket fits standard 3/8 inch drive ratchets, extension bars, and torque wrenches. It is suited for HVAC equipment servicing, automotive repair, and general mechanical maintenance where spline fasteners are used. The 1/2 inch hex size and 16-spline configuration are common on factory-installed fasteners found in compressors, drive assemblies, and mechanical panels. The socket meets Federal Spec GGG-W-641e and ANSI Spec B107.1, making it appropriate for government contract and commercial service environments.

Key Features

• 3/8 inch drive accepts standard ratchets, extensions, and torque wrenches
• 16-spline configuration matches spline-type fasteners in mechanical assemblies
• 1/2 inch hex size for precise fastener engagement
• 12-point internal geometry reduces fastener rounding risk
• Meets Federal Spec GGG-W-641e and ANSI Spec B107.1
• Lightweight at 0.07 pounds for extended use without fatigue

Compatibility

Designed as an OEM-style replacement socket for use with standard 3/8 inch drive hand-tool sets requiring spline socket fitment.

Installation Notes

This socket is installed and used by licensed mechanics, HVAC technicians, and industrial maintenance professionals. Always ensure the drive tool is rated for the torque being applied and that the socket is fully seated on the fastener before turning. Inspect the socket for wear or cracking before each use. Follow applicable workplace safety codes when working in confined spaces or on energized equipment.