Precision Twist Drill 5998978 Taper Length Drill Bit

Product Description

The PRECISION TWIST DRILL 5998978 is a taper length, straight-shank drill bit designed for general-purpose drilling in a wide range of metals and engineered materials. Manufactured from high speed steel with a bright/uncoated finish, it delivers reliable performance across production and maintenance applications. The bit measures 1.0313 inches in diameter with a 118-degree standard point angle and a right-hand spiral flute. A web-thinned, tapered web configuration reduces thrust at entry, improving hole quality and reducing tool deflection. The overall length is 11.125 inches, with a flute length of 6.5 inches, providing the extended reach needed for deep-hole work that standard-length bits cannot access.

This drill bit suits machinists, maintenance technicians, and fabricators working in job shops, manufacturing facilities, and field maintenance environments. The taper length design is particularly useful when drilling through thick stock or when additional reach is required beyond what a jobber-length bit provides. The Series R51 geometry is rated for general-purpose use and is appropriate for both manual drill press setups and CNC drilling operations where a straight-shank tool is specified.

Key Features

• 1.0313-inch diameter with 1.0312-inch straight shank for secure chuck engagement
• 118-degree standard point angle with web-thinned, tapered web for reduced entry thrust
• 6.5-inch spiral flute length provides extended reach for deep-hole applications
• High speed steel construction supports drilling in a broad range of materials
• Bright/uncoated finish suitable for general-purpose use without specialized coolant requirements
• Right-hand cut, regular spiral, ANSI-compliant Series R51 geometry

Compatibility

Designed as a general-purpose taper length drill bit compatible with materials including alloy steel, aluminum, aluminum alloy, brass, bronze, carbon steel, cast iron, copper, graphite, hardened steel, high strength bronze, magnesium, magnesium alloy, malleable iron, nickel, nickel alloy, reinforced plastic materials, cermet, and stainless steel.

Installation Notes

Installation and use of this bit is performed by machinists or qualified maintenance technicians operating drill presses, lathes, or CNC machining centers. Secure the straight shank fully in a compatible chuck before operation and verify runout before drilling. Power down and lock out the machine before changing tooling. Do not exceed the recommended feed and speed parameters for the workpiece material, and use appropriate cutting fluid where required by the material being drilled.