Proto J4990-10MST Hand Hex Bit Socket 3/8 in Drive 10mm

Product Description

The PROTO J4990-10MST is a hand hex bit socket designed for use with a 3/8 inch drive ratchet or torque wrench. It accepts a 10 mm hex bit and measures 1-49/64 inches in overall length, making it suitable for fastener access in confined spaces. This socket is intended for professional hand-tool applications across mechanical, HVAC, plumbing, and electrical service work where hex-drive fasteners are common. At 0.12 pounds, it is a lightweight single-piece tool built for repetitive fastener-driving tasks in both shop and field environments.

This hex bit socket fits standard 3/8 inch drive tool setups and is appropriate for residential and commercial service work. It is well suited for technicians who routinely encounter 10 mm hex fasteners on equipment panels, motor mounts, access covers, and similar hardware. The 1-49/64 inch overall length provides clearance in moderately confined installations without sacrificing drive engagement.

Key Features

• 3/8 inch drive interface compatible with standard ratchets, extensions, and torque wrenches
• 10 mm hex bit size for precise engagement on metric hex fasteners
• 1-49/64 inch overall length suits tight-clearance applications
• Lightweight at 0.12 pounds for reduced hand fatigue during extended use
• Single-piece socket construction for consistent torque transfer

Compatibility

Designed as a standard-fitment hex bit socket for use with any 3/8 inch drive hand tool, including ratchets, breaker bars, and torque wrenches that accept square-drive accessories.

Installation Notes

Installation is performed by hand tool technicians across mechanical and service trades. Confirm the drive square is fully seated before applying torque to avoid slippage or fastener damage. Inspect the hex bit socket for wear or rounding before use, particularly on high-torque applications. No power tools should be used with a hand-rated socket unless the socket is explicitly rated for impact use.