Precision Twist Drill 5999856 Reduced Shank Drill Bit

Product Description

The PRECISION TWIST DRILL 5999856 is a reduced shank twist drill bit designed for general-purpose drilling in metalworking and fabrication applications. The bit measures 1-1/64 inches (1.0156 inches decimal) in diameter with a 1/2-inch straight-cylindrical reduced shank, allowing it to seat in standard 1/2-inch drill chucks despite the larger cutting diameter. Manufactured from high-speed steel (HSS) with a bright, uncoated finish, it features a 118-degree standard point angle suited for drilling ferrous metals and a wide range of secondary materials. Overall length is 6 inches with a 3-inch flute length. Right-hand cut with a regular spiral flute pattern. Part of the Series R56 line.

This bit is used in machining, maintenance, and fabrication environments where a drill diameter larger than 1/2 inch is needed but only a 1/2-inch chuck is available. The reduced shank design bridges that gap without requiring a larger spindle or chuck upgrade. Suitable for drilling ferrous metals as the primary workpiece material. Secondary materials include aluminum, copper, magnesium, nickel, titanium, cermet, and synthetic materials. Typically used by machinists, millwrights, pipefitters, and maintenance technicians on drill presses, lathes, or heavy-duty hand drills.

Key Features

• 1-1/64 inch (1.0156 inch) cutting diameter with 1/2-inch reduced shank for standard chuck compatibility
• High-speed steel construction for durability across ferrous and non-ferrous materials
• 118-degree standard point angle for general-purpose drilling without requiring a pilot hole in most applications
• Right-hand cut with regular spiral flute pattern for efficient chip evacuation
• Bright, uncoated finish — suitable for use with or without cutting fluid
• Series R56 design meets ANSI standards

Compatibility

Designed for use in any 1/2-inch capacity drill chuck. Compatible with drill presses, lathes, and heavy-duty hand drills accepting straight-cylindrical shanks. Suitable for ferrous metal as the primary workpiece material, with secondary suitability for aluminum, copper, magnesium, nickel, titanium, cermet, and synthetic materials per manufacturer specifications.

Installation Notes

Secure the 1/2-inch reduced shank fully into the chuck before operation and verify chuck is tightened with a chuck key where applicable. When drilling larger diameters in hard metals, a pilot hole is recommended to reduce walking and extend bit life. Always wear appropriate eye protection and follow applicable shop safety procedures. No coolant through-spindle is required for this bit, though external cutting fluid may be applied for ferrous metal drilling at depth.