Precision Twist Drill 5999903 Reduced Shank Drill Bit

Product Description

The PRECISION TWIST DRILL 5999903 is a reduced shank twist drill bit designed for general-purpose drilling in metalworking and fabrication applications. The bit measures 1-3/64 inches (1.0469 inches decimal) in cutting diameter with a 1/2-inch straight-cylindrical shank, allowing use in standard chucks that cannot accommodate the full cutting diameter. Ground from high speed steel (HSS) with a bright, uncoated finish, this bit delivers consistent performance across a wide range of ferrous and non-ferrous materials. The 118-degree standard point angle suits most everyday drilling tasks without requiring specialized point preparation.

This bit is intended for trade professionals and machinists working in HVAC fabrication shops, plumbing rough-in, electrical panel work, or general metal fabrication where large-diameter holes are needed but only a 1/2-inch chuck is available. The Series R56 designation identifies it within the PRECISION TWIST DRILL line of reduced shank jobber-style bits. Suitable for drilling ferrous metals, aluminum, copper, nickel, magnesium, titanium, and synthetic materials. The 3-inch flute length accommodates a maximum drilling depth of 3 inches, making it appropriate for most standard material thicknesses encountered in trade work.

Key Features

• Reduced shank design: 1/2-inch shank accepts standard drill chucks while cutting a 1-3/64 inch diameter hole
• High speed steel construction for durability across ferrous and non-ferrous workpiece materials
• 118-degree standard point angle for general-purpose drilling without special point grinding
• Right-hand cut with regular spiral flute geometry for efficient chip evacuation
• Bright, uncoated finish suitable for use with or without cutting fluid
• 6-inch overall length with 3-inch flute length supports a maximum drilling depth of 3 inches

Compatibility

Designed for use in any drill press, milling machine, or portable drill with a 1/2-inch or larger chuck. Compatible with ferrous metals, aluminum, copper, magnesium, nickel, titanium, and synthetic materials per Series R56 general-purpose specifications.

Installation Notes

Installation and use should be performed by a qualified machinist or tradesperson familiar with drill press and portable drill operation. Secure the workpiece properly before drilling to prevent rotation or movement. Follow ANSI safety standards for drilling operations, including use of appropriate eye protection and secure chuck engagement. Apply cutting fluid when drilling hard ferrous metals to extend tool life and improve hole quality.