Precision Twist Drill 5999546 Reduced Shank Drill Bit

Product Description

The PRECISION TWIST DRILL 5999546 is a reduced shank twist drill bit designed for drilling into ferrous metals and a range of secondary materials including aluminum, copper, nickel, titanium, and magnesium. It measures 1-1/4 inches in diameter with a 1/2 inch Weldon shank, allowing it to chuck into standard 1/2 inch capacity drill chucks and milling machine spindles. The 118-degree standard point angle suits general-purpose hole-making in production and maintenance environments. Overall length is 6 inches with a 3 inch flute length and a maximum drilling depth of 3 inches. The bright uncoated finish is appropriate for use without coolant in typical shop and field conditions. Machinists, tool-and-die workers, pipefitters, and mechanical contractors commonly use bits of this type.

This bit is built for general-purpose drilling in ferrous metal fabrication, structural steel work, pipefitting, and mechanical assembly. The Weldon shank with three flats prevents slipping under torque in side-lock holders and end mill adapters, making it suitable for drill press, milling machine, and heavy-duty handheld applications. Secondary workpiece materials include aluminum, cermet, copper, magnesium, nickel, synthetic composites, and titanium, giving this bit utility across mixed-material jobsite scenarios. Series R57 designates it within the PRECISION TWIST DRILL general-purpose high speed steel line.

Key Features

• 1-1/4 inch cutting diameter with 1/2 inch reduced Weldon shank for use in standard 1/2 inch chucks and side-lock holders
• 118-degree standard point angle for general-purpose entry into ferrous and non-ferrous metals
• High speed steel construction provides toughness and heat resistance without coolant
• 3-flat Weldon shank prevents rotation and slippage under high-torque conditions
• Right-hand spiral flute with regular helix evacuates chips efficiently during through-hole drilling
• Bright uncoated finish — suitable for dry cutting across a broad range of workpiece materials

Compatibility

Designed as a general-purpose replacement or production drill bit for use in 1/2 inch capacity drill chucks, Weldon-style side-lock holders, and end mill adapters on drill presses and milling machines. Compatible with ferrous metals as the primary workpiece material; rated for secondary use in aluminum, cermet, copper, magnesium, nickel, synthetic, and titanium workpieces per ANSI standards.

Installation Notes

Installation and use should be performed by a qualified machinist or mechanical tradesperson familiar with rotating cutting tools. Secure the Weldon shank firmly in a side-lock holder or chuck before operation, ensuring all three flats are properly engaged with set screws where applicable. Verify drill press or machine spindle speed is set appropriately for the workpiece material and bit diameter before starting the cut. Eye protection and appropriate workholding are required; never hand-hold the workpiece during drilling.