Precision Twist Drill 5999947 Reduced Shank Drill Bit

Product Description

The PRECISION TWIST DRILL 5999947 is a reduced shank twist drill bit designed for general-purpose hole-making in metal fabrication, maintenance, and mechanical work. The bit measures 13/16 inches (0.8125 inches) in diameter with a 1/2 inch straight-cylindrical shank, allowing it to seat in standard 1/2 inch drill chucks where a full-size shank would not fit. Constructed from high speed steel with a bright uncoated finish, it carries a 118-degree standard point angle and cuts right-hand with a regular spiral flute. Machinists, millwrights, and general tradespeople reach for this bit when drilling mid-to-large diameter holes without a larger chuck capacity.

The 5999947 is rated for ferrous metals as its primary workpiece material and handles a broad secondary range including aluminum, copper, nickel, magnesium, titanium, and synthetic materials. With a 3 inch flute length and 6 inch overall length, it provides enough reach for through-holes in plate stock, structural steel, and pipe flanges. The Series R56 designation places it within PRECISION TWIST DRILL's standard general-purpose line, conforming to ANSI standards. No coolant system is required, making it practical for both floor-standing drill presses and hand-held electric drills.

Key Features

• 13/16 inch (0.8125 inch) drill diameter with 1/2 inch reduced shank for standard chuck compatibility
• 118-degree standard point angle for reliable self-centering on flat and curved metal surfaces
• High speed steel construction handles intermittent heat and repeated use on ferrous and non-ferrous metals
• Right-hand cut, regular spiral flute with 3 inch flute length for efficient chip evacuation
• Bright uncoated finish — no coating delamination risk in demanding drilling applications
• ANSI-compliant Series R56 geometry for consistent, predictable performance

Compatibility

Designed as a general-purpose replacement or service drill bit compatible with any 1/2 inch drill chuck. Suitable for drill presses, magnetic base drills, and heavy-duty hand drills accepting straight-cylindrical shanks.

Installation Notes

Installation should be performed by a qualified machinist or tradesperson familiar with drill press or hand-drill operation. Always secure the workpiece with a vise or clamps before drilling — never hand-hold metal stock. Confirm the chuck is fully tightened and the bit is concentric before starting the spindle. Reduce feed pressure as the bit breaks through to prevent grabbing or bit breakage.