Proto J5278HA 11/16 in 6-point 3/8 Dr Universal Flex Socket

Product Description

The PROTO J5278HA is a 6-point hand socket designed for professional-grade fastener work in tight or angled access situations. Built from alloy steel with a chrome-plated finish, this socket fits an 11/16 inch fastener and accepts a 3/8 inch drive. Its universal/flex head allows the drive to pivot relative to the socket body, giving technicians working clearance around obstructions without sacrificing torque transfer. At just under 2 inches in overall length, it is compact enough for confined engine bays, equipment panels, and mechanical assemblies. Manufactured to ASME B107.1 standards, it is suited for daily use in automotive, HVAC, plumbing, and general mechanical service.

This socket is intended for hand-tool use by automotive technicians, HVAC service technicians, plumbers, electricians, and other trade professionals who regularly work in constrained spaces. The universal/flex joint is particularly useful in engine compartments, equipment rooms, and anywhere a straight-drive approach is blocked by surrounding components. It is packaged as a single unit and is compatible with standard 3/8 inch drive ratchets, extensions, and breaker bars. Its chrome finish resists corrosion and simplifies cleaning of grease and debris after use in the field.

Key Features

• Universal/flex head design allows pivot access to fasteners obstructed by surrounding components
• 6-point socket geometry provides full-face contact on hex fasteners, reducing rounding risk
• Alloy steel construction with chrome-plated finish for durability and corrosion resistance
• Fits 11/16 inch fasteners with a 3/8 inch drive interface
• Overall length of approximately 1-31/32 inches for compact fitment in tight spaces
• Manufactured to ASME B107.1 standards for hand socket performance and dimensional tolerances

Compatibility

Designed for use with standard 3/8 inch drive ratchets, breaker bars, and extensions. The 11/16 inch socket size fits standard SAE hex fasteners of that designation.

Installation Notes

This socket is a hand-tool accessory installed by the technician onto a compatible 3/8 inch drive ratchet or breaker bar before use. Ensure the drive connection is fully seated and the flex joint is not over-extended beyond its rated pivot range during torque application. Do not use impact drivers or impact wrenches with hand-rated sockets. Inspect the socket for cracks or wear before each use, and remove from service if damage is found.