Precision Twist Drill 5999570 Reduced Shank Drill Bit

Product Description

The PRECISION TWIST DRILL 5999570 is a reduced shank twist drill bit designed for drilling large-diameter holes using standard 1/2 inch capacity chucks. The full drill diameter measures 1.2344 inches (1-15/64 inch), while the Weldon flat shank reduces to 0.5 inches to fit common drill press and machining center chuck sizes. Built from high-speed steel with a bright uncoated finish, it features a 118-degree standard point angle and a right-hand spiral flute. Machinists, fabricators, and maintenance technicians use this bit for general-purpose hole making in ferrous metals and a range of secondary workpiece materials. The three-flat Weldon shank resists slipping under torque.

The 5999570 is suited for general-purpose drilling in ferrous metals as its primary workpiece material. It also handles aluminum, copper, magnesium, nickel, titanium, cermet, and synthetic materials. The 3-inch flute length provides adequate chip clearance for holes up to the maximum drilling depth of 3 inches. At 6 inches overall length, the bit fits standard drill press setups and knee-mill operations. The Series R57 designation places it within a recognized line of reduced shank tooling manufactured to ANSI standards. No coolant-through capability is present, so flood or mist cooling at the cutting face is the recommended approach for sustained production drilling.

Key Features

• Reduced shank design: 1.2344 inch cutting diameter with 0.5 inch Weldon flat shank fits 1/2 inch capacity chucks
• Three-flat Weldon shank prevents bit rotation and slippage under high torque loads
• 118-degree standard point angle for general-purpose drilling across a wide range of materials
• High-speed steel construction with bright uncoated finish for use across ferrous and non-ferrous applications
• Right-hand spiral flute with regular helix promotes efficient chip evacuation up to 3 inches depth
• Conforms to ANSI standards; Series R57 reduced shank classification

Compatibility

Designed as a general-purpose reduced shank drill bit compatible with drill presses, knee mills, and machining centers equipped with 1/2 inch capacity chucks or collets.

Installation Notes

Install in a 1/2 inch drill chuck or collet and tighten securely against the Weldon flats to prevent axial slippage during operation. Ensure the machine spindle is fully stopped and locked out before mounting or removing the bit. For sustained drilling at this diameter, apply flood or mist coolant to the cutting face to manage heat buildup and extend tool life. Verify workpiece clamping is secure before beginning the cut, as large-diameter bits produce significant torque reaction forces.