Klein Tools Keystone Screwdriver 600-6 5/16 Inch Tip Flathead Wrench Assist 6 Inch Square Shank Cushion Grip Hand Tool For Rusted Stubborn Fasteners

High-Torque Square Shank Keystone Screwdriver with Wrench Assist Bolster for Stubborn Fasteners

The Klein Tools 600-6 5/16-Inch Keystone Screwdriver delivers a commercial-grade fastening solution engineered to break loose heavily rusted, painted, or over-tightened flathead hardware in industrial or electrical settings. Fabricated in the USA from heat-treated alloy steel with a premium chrome plating, this industrial hand tool features a robust 6-inch square shank optimized to accept open-end wrenches or pliers for amplified torque transmission. The precision-machined 5/16-inch keystone tip is ground to exact tolerances to fit securely inside screw slots and significantly reduce driver cam-out. Inside the handle, integral flanges anchor the blade deeply to form a twist-resistant lock under heavy wrench assistance, while the signature Cushion-Grip handle ensures non-slip user comfort and resists degradation from oil, gas, and water.

Best Used For:

• Rusted Fastener Removal: Applying external mechanical leverage via a wrench to break loose frozen, oxidized flathead screws on heavy machinery.
• Commercial Electrical Assemblies: Driving wide-slotted grounding screws and terminal panel hardware requiring high initial seating torque.
• Industrial Maintenance Operations: Servicing heavy mechanical equipment where paint-filled or over-torqued slotted fasteners are present.

Key Performance & Safety Features

• Square Shank Wrench Assist: Structural square shaft profile permits direct wrench engagement to safely multiply manual rotational force vectors.
• Precision Machined Keystone Tip: Heavy-duty 5/16-inch flathead tip configuration fills screw slots fully to prevent side-slippage and component marring.
• Flanged Blade Anchor: Interlocking internal steel flanges secure the shaft inside the handle housing to stop spinning under high mechanical stress.
• Cushion-Grip Handle: Resilient rubberized handle jacket optimizes physical hand surface contact while mitigating user palm fatigue.
• Tip-Ident Markings: Permanent tip type and orientation symbols printed on the handle crown support rapid tool selection in service pouches.

What's Included

• (1) 5/16 In. Keystone Screwdriver with 6 In. Square Shank (600-6)

Technical Specifications

Pro-Tip: When deploying an open-end wrench to extract seized fasteners, apply firm downward palm pressure directly onto the screwdriver handle crown before turning. This action locks the 5/16-inch keystone tip completely within the slot, avoiding upward tool lift and protecting the driver from slippage.