Kennametal 5990938 Solid Carbide Jobber Drill Letter G

Product Description

The KENNAMETAL 5990938 is a solid carbide jobber-length drill bit sized to Letter G (0.2610 inches / 6.63 mm) with a 135-degree split-point geometry. It runs right-hand cutting with a regular spiral flute and a 3-flat flatted shank for secure chuck retention. Overall length is 3.5827 inches (91.00 mm) and flute length is 2.0866 inches (53.00 mm). The bright, uncoated finish and solid carbide construction make it well suited for high-speed drilling where coating compatibility with cutting fluids or workpiece chemistry is a consideration. Coolant-through capability supports efficient chip evacuation and heat management in deeper holes. This drill is installed and used by machinists, tool-and-die technicians, and precision fabricators.

This jobber drill is designed for use in aluminum, non-ferrous metals, and similar materials where carbide rigidity and sharp edge retention are required. The 5xD flute-to-diameter ratio and 43.00 mm maximum drilling depth (1.693 inches) suit it for general-purpose hole-making in CNC machining centers, drill presses, and manual mills where a letter-size bore is specified. The 3-flat shank diameter of 8 mm provides positive anti-rotation engagement in compatible toolholders and chucks.

Key Features

• Solid carbide construction for rigidity and edge retention in non-ferrous and aluminum applications
• 135-degree point angle reduces entry force and walking on flat or curved surfaces
• Coolant-through design supports chip evacuation and thermal control in deeper bores
• 3-flat shank prevents rotation in compatible chucks and toolholders
• Bright, uncoated finish compatible with a wide range of cutting fluids without chemical interaction concerns
• Diameter tolerance of 0.0002 to 0.0008 inches for controlled hole sizing

Compatibility

Designed as a jobber-length replacement drill for applications requiring a Letter G (0.2610-inch) bore in aluminum and non-ferrous workpieces. Fits toolholders and chucks accepting an 8 mm, 3-flat shank.

Installation Notes

This drill is installed by machinists and CNC operators in standard drill chucks or collet-style toolholders sized for an 8 mm shank. Confirm machine spindle is fully powered down and locked out before changing tooling. Secure the 3-flat shank firmly to prevent slippage under cutting load. Use appropriate cutting fluid or coolant through the spindle when drilling deeper holes to maximize tool life and maintain tolerance.