Klein Tools 646-5/16 5/16-Inch Nut Driver 6-Inch Hollow Shaft pneumatic accessory

5/16-Inch Nut Driver with 6-Inch Hollow Shaft

This Klein Tools nut driver fits 5/16-inch SAE fasteners and features a six-inch hollow round shank that provides bolt clearance for longer studs. The cushion grip adds comfort during repetitive tightening or loosening tasks. It is a non-magnetic, non-insulated hand tool suited for automotive, electrical and general mechanical work where a deep-reach driver is required.

Installation and common issues

Select the driver that matches the fastener size, seat the tip fully on the nut or bolt head, and apply steady torque by hand or with a compatible power tool. The hollow shaft allows the fastener to pass through, but debris or damaged threads can prevent full engagement. The cushion grip is not rated for electrical insulation, so do not use it on live circuits. Excessive force on corroded hardware may round the fastener corners.

Capacity and headroom

The tool handles standard 5/16-inch SAE hex fasteners and clears bolts up to the full six-inch shank length, making it practical for deep-set or threaded-rod applications. It lacks a magnetic tip, so the fastener must be held or started by hand in tight spaces. For larger hex sizes, smaller drives, or insulated work, a different driver is required.