Klein Tools 640-7/16 Hollow Shaft Nut Driver 7/16 Hex

Product Description

The KLEIN TOOLS 640-7/16 is a hollow shaft nut driver built for trade professionals who need to drive hex fasteners over threaded rod or long bolt shanks without obstruction. The 7/16 inch hex drive engages standard hex nuts and sheet metal screws commonly found in electrical panels, HVAC equipment, and electrical enclosures. The 3 inch shank is heat treated, tempered, and chrome plated steel for durability under torque. A plastic-dipped shank finish adds grip and corrosion resistance. The cushion grip handle is brown and designed for extended use without hand fatigue. This driver is sold individually and is suited for electricians, HVAC technicians, and panel installers working in tight or repetitive fastening applications.

The 640-7/16 is a standard hand tool used across residential and commercial electrical and HVAC installation work. It is particularly useful when driving nuts onto threaded studs where a standard closed-end driver cannot fully seat. Electricians reach for this tool when terminating equipment in load centers, junction boxes, and control panels. HVAC technicians use it when securing blower assemblies, control board standoffs, and cabinet fasteners. The hollow shaft passes fully over exposed threads, allowing the driver to seat flush on the nut face regardless of fastener protrusion length.

Key Features

• 7/16 inch hex drive fits standard hex nuts and sheet metal screws
• Full hollow shaft design accommodates threaded rod and long bolt shanks
• 3 inch shank length provides clearance in shallow panels and enclosures
• Heat treated, tempered, chrome plated steel shank resists wear and corrosion
• Cushion grip handle reduces hand fatigue during repetitive fastening
• Plastic-dipped shank provides additional corrosion protection

Compatibility

Designed as a standard hollow shaft nut driver for use with 7/16 inch hex fasteners commonly found in electrical, HVAC, and light mechanical applications requiring passage over threaded rod or extended bolt shanks.

Installation Notes

This tool is used by electricians and HVAC technicians working on live or de-energized equipment. Always de-energize and lock out electrical panels before performing fastener work inside enclosures, following NFPA 70E guidelines. Use the hollow shaft to fully seat the driver on the nut before applying torque to avoid rounding fastener flats. Inspect the shank and handle for cracks or damage before each use.

Technical Specifications

• Drive Size: 7/16 inch hex
• Shank Length: 3 inches
• Shaft Type: Hollow
• Shank Material: Heat treated tempered chrome plated steel
• Handle Type: Cushion grip
• Handle Color: Brown
• Handle Material: Plastic
• Weight: 0.39 pounds
• UPC: 092644650260

Standard Information

• Brand: KLEIN TOOLS
• Manufacturer Part Number: 640-7/16