Precision Twist Drill 5999670 Reduced Shank Drill Bit

Product Description

The PRECISION TWIST DRILL 5999670 is a reduced shank twist drill bit designed for general-purpose drilling in ferrous metals, aluminum, copper, titanium, and a range of other materials. It features a 51/64 inch (0.7969 inch decimal) cutting diameter with a reduced 1/2 inch straight-cylindrical shank, allowing it to be chucked in standard 1/2 inch drill chucks without requiring a larger chuck capacity. The bit is manufactured from high speed steel with a bright uncoated finish and ground to a standard 118-degree point angle for reliable starts on flat and curved surfaces. Overall length is 6 inches with a 3 inch flute length, supporting a maximum drilling depth of 3 inches.

This bit is well suited for metal fabrication shops, maintenance and repair operations, and general industrial drilling tasks. The Series R56 designation places it in PRECISION TWIST DRILL's standard general-purpose line. The reduced shank design is particularly useful when drilling large-diameter holes with equipment limited to 1/2 inch chuck capacity, a common situation on portable drill presses, handheld power drills, and light machine tools. Right-hand spiral flutes clear chips efficiently in ferrous and non-ferrous workpieces alike.

Key Features

• 51/64 inch cutting diameter with reduced 1/2 inch shank for use in standard 1/2 inch chucks
• High speed steel construction for durability across ferrous and non-ferrous materials
• 118-degree standard point angle for general-purpose entry and self-centering starts
• 3 inch flute length with regular spiral for consistent chip evacuation
• Bright uncoated finish — no coating buildup that can affect tolerance on close-fit holes
• Right-hand cut, ANSI standard geometry

Compatibility

Designed for use in any drill press, milling machine, or power drill with a 1/2 inch or larger chuck. Suitable for drilling ferrous metals, aluminum, copper, magnesium, nickel, titanium, synthetic materials, and cermet. Conforms to ANSI standards.

Installation Notes

Secure the bit fully in a 1/2 inch chuck and verify the shank is seated straight before applying load. Always wear appropriate eye protection and secure the workpiece before drilling. Use cutting fluid or coolant on harder ferrous materials to extend bit life, even though this bit is rated for dry use. High speed steel bits should not be used at feeds and speeds intended for carbide tooling.