Precision Twist Drill 5999690 Reduced Shank Drill Bit

Product Description

The PRECISION TWIST DRILL 5999690 is a reduced shank twist drill bit designed for general-purpose drilling in ferrous metals, aluminum, copper, and a range of other materials. It features a 59/64 inch (0.9210 inch decimal) cutting diameter paired with a 1/2 inch straight-cylindrical shank, allowing it to be chucked in standard 1/2 inch drill chucks without requiring a larger machine spindle. The drill is manufactured from high speed steel (HSS) with a bright, uncoated finish. The 118-degree standard point angle is the conventional geometry suited for drilling into steel, cast iron, and non-ferrous materials. Overall length is 6 inches with a 3-inch flute length, classifying it as a reduced shank, regular-spiral jobber-style bit. It is part of the Series R56 line.

This bit is suited for use in machine shop, maintenance, and fabrication environments where the hole diameter required exceeds the capacity of standard 1/2 inch shank tooling but a reduced shank design allows the operator to use existing equipment. Right-hand cutting direction makes it compatible with conventional drill presses, milling machines, and handheld electric drills. Typical workpiece materials include ferrous metals, aluminum, copper, magnesium, nickel alloys, titanium, and synthetic materials. Maximum drilling depth matches the 3-inch flute length.

Key Features

• 59/64 inch cutting diameter (0.9210 inch decimal) with a 1/2 inch reduced shank for use in standard 1/2 inch chucks
• High speed steel construction for strength and wear resistance across ferrous and non-ferrous materials
• 118-degree standard point angle for general-purpose drilling without specialized point grinding
• Regular spiral flute geometry promotes chip evacuation during drilling
• Bright, uncoated finish — no coating thickness to account for in hole tolerance
• Right-hand cut; compatible with all standard rotary drilling equipment
• ANSI-standard dimensions for consistent fitment and interchangeability

Compatibility

Designed as a general-purpose reduced shank drill bit per ANSI standards, compatible with 1/2 inch keyed or keyless drill chucks on drill presses, lathes, milling machines, and heavy-duty handheld drills. Suitable for ferrous metals, aluminum, copper, magnesium, nickel, titanium, and synthetic materials.

Installation Notes

Installation and use should be performed by a qualified machinist or trades professional familiar with rotating cutting tool safety. Secure the 1/2 inch shank fully in the drill chuck before operation and verify the chuck is tightened properly to prevent bit slippage under load. Always wear appropriate eye protection and ensure the workpiece is clamped securely before drilling. Inspect the cutting edges for wear or chipping before each use; a dull or damaged bit should be resharpened or replaced before continuing work.