Precision Twist Drill 5995790 Extra Length Drill Bit

Product Description

The PRECISION TWIST DRILL 5995790 is a high-speed steel extra length drill bit engineered for deep-hole drilling in demanding trade and industrial applications. Built on the QC0860P series platform, it measures 31/64 inch (0.4844 inch decimal) in diameter with an 8-inch overall length and a 6-inch parabolic flute. The 135-degree split point reduces walking and cutting torque at entry, while the parabolic flute geometry improves chip evacuation in deep bores. The bright uncoated finish keeps surface hardness intact without adding coating thickness, which matters in tight-tolerance work. Licensed machinists, maintenance technicians, and fabricators reaching for extended reach in confined bores are the primary users.

This bit is suited for deep-hole drilling in structural, mechanical, and fabrication work where a standard-length bit cannot reach. The extra length makes it practical for drilling through thicker stock, stacked materials, or into recessed cavities in assemblies. It cuts right-hand and handles a broad range of workpiece materials including carbon steel, alloy steel, stainless steel, aluminum, brass, bronze, cast iron, copper, nickel alloys, magnesium, and reinforced plastics. Web thinning with a parallel web configuration reduces thrust requirements and helps maintain center on entry.

Key Features

• 135-degree split point reduces bit walking and lowers entry thrust force
• Parabolic flute design accelerates chip removal in deep bores
• 8-inch overall length with 6-inch flute length for extended reach applications
• High-speed steel construction with bright uncoated finish for consistent surface hardness
• Web-thinned parallel web configuration reduces cutting resistance
• Right-hand cutting direction; compatible with standard drill presses, magnetic drills, and hand drills

Compatibility

Compatible workpiece materials include alloy steel, aluminum, aluminum alloy, brass, bronze, carbon steel, cast iron, cermet, copper, graphite, hardened steel, high strength bronze, magnesium, magnesium alloy, malleable iron, nickel, nickel alloy, reinforced plastic materials, and stainless steel. Fits any standard straight-shank drill chuck accepting a 31/64 inch shank.

Installation Notes

Secure the shank fully in a properly sized chuck before operation and verify chuck key removal before starting the drill. Use appropriate cutting fluid or coolant for the workpiece material to extend tool life, particularly in steel and stainless applications. Reduce feed pressure when the point breaks through to prevent bit deflection or workpiece damage. Inspect the cutting edges for chipping or wear before each use, especially after drilling hardened or abrasive materials.