Proto J49905/16ST Hand Hex Bit Socket 3/8 in Drive

Product Description

The PROTO J49905/16ST is a hand hex bit socket designed for manual torque applications in trade and industrial settings. It accepts a 3/8 inch square drive and drives a 5/16 inch hex fastener. Overall length is 1-13/16 inches with a 3/4 inch bit length, making it a compact tool suited for tight-clearance work. Licensed mechanics, HVAC technicians, plumbers, and electricians use this type of socket when precise hand torque is needed on hex-head fasteners, set screws, and similar hardware. The short profile reduces interference in confined installations.

This hex bit socket fits standard 3/8 inch drive hand ratchets, T-handles, and breaker bars. It is appropriate for residential and light commercial service work where hex fasteners appear on equipment panels, valve packing glands, fan assemblies, and electrical enclosures. The 5/16 inch hex size is common across a wide range of HVAC, plumbing, and electrical hardware encountered in the field.

Key Features

• 3/8 inch square drive for compatibility with standard hand ratchets and drive tools
• 5/16 inch hex bit size for direct fastener engagement without an adapter
• Compact 1-13/16 inch overall length suited for restricted-access fastener locations
• 3/4 inch bit length provides adequate engagement depth on typical hex fasteners
• Single-piece socket construction for consistent torque transfer

Compatibility

Designed for use with standard 3/8 inch drive hand tools including ratchets, T-handles, and extension bars. Fits 5/16 inch hex fasteners as encountered across HVAC, plumbing, electrical, and general mechanical service applications.

Installation Notes

Install and remove hex fasteners with hand torque only when using this socket on a standard 3/8 inch drive ratchet or T-handle. Verify the hex bit is fully seated in the fastener recess before applying torque to avoid rounding the fastener head. When working near energized electrical components, de-energize and lock out equipment per applicable NFPA 70E procedures before using any hand tool in the work area.