Precision Twist Drill 5997161 Jobber Drill Bit 21/64

Product Description

The PRECISION TWIST DRILL 5997161 is a jobber-length drill bit designed for general-purpose drilling in a wide range of materials. It carries a 21/64 inch (0.3281 inch decimal) diameter and is manufactured from high-speed steel with a bright, uncoated finish. The 135-degree split point reduces walking on entry and lowers thrust requirements compared to a standard 118-degree point. A parabolic spiral flute with web thinning promotes efficient chip evacuation and helps maintain cutting performance in deeper holes. This bit is suited for use by machinists, pipefitters, HVAC technicians, electricians, and plumbers drilling through ferrous and non-ferrous metals during fabrication or service work.

The 5997161 is appropriate for drilling steel, stainless steel, cast iron, non-ferrous metals, superalloys, titanium, and other hard materials. The straight cylindrical shank fits standard 3-jaw drill chucks found on portable drills, drill presses, and magnetic base drills. With a flute-to-diameter ratio of 10xD, this bit handles depths up to 3-5/16 inches, making it practical for structural steel, sheet metal stacks, pipe flanges, and panel work encountered in mechanical and electrical trade applications.

Key Features

• 135-degree split point reduces drill walking and decreases feed force on entry
• High-speed steel construction provides durability across steel, stainless steel, cast iron, and non-ferrous metals
• Parabolic spiral flute with web thinning improves chip evacuation and reduces heat buildup
• Straight cylindrical shank fits standard 3-jaw chucks without adapters
• Maximum drilling depth of 3-5/16 inches supports most field and shop drilling tasks
• ANSI-standard geometry; heavy-duty grade for demanding applications

Compatibility

Designed as a general-purpose jobber-length drill bit compatible with any standard 3-jaw drill chuck accepting a 21/64 inch straight cylindrical shank. Suitable for portable drills, benchtop drill presses, and magnetic base drills used in trade and shop environments.

Installation Notes

Installation is performed by machinists and trade professionals using standard drill chucks; secure the shank fully and verify chuck tightness before operation. Always wear appropriate eye protection and ensure the workpiece is firmly clamped before drilling. For best results in stainless steel and hard alloys, use cutting fluid to reduce heat and extend bit life. Do not exceed the manufacturer-rated maximum drilling depth of 3-5/16 inches per pass without retracting to clear chips.