Precision Twist Drill 5999721 Cobalt Jobber Drill 29/64 in

Product Description

The PRECISION TWIST DRILL 5999721 is a cobalt jobber-length drill bit designed for high-performance drilling in steel and other demanding workpiece materials. It features a 29/64 inch (0.4531 inch) diameter, a 135-degree split-point tip, and a right-hand regular spiral flute geometry. The oxide and straw coating reduces friction and extends tool life during production drilling. Web thinning at the tip lowers entry force and improves chip evacuation. This bit is built to heavy-duty grade standards and is suited for use by machinists, pipefitters, and maintenance trades working with ferrous metals.

The 5999721 fits standard drilling applications in steel, stainless, cast iron, and non-ferrous materials. It is a general-purpose jobber bit appropriate for bench drill presses, magnetic-base drills, and hand-held power drills where a straight shank chuck is used. The 5-19/32 inch overall length and 3-45/64 inch flute length make it well suited for through-hole and moderate-depth drilling in plate, structural steel, and pipe work encountered in mechanical, plumbing, and electrical rough-in tasks.

Key Features

• Cobalt high-speed steel construction for heat resistance in steel drilling applications
• 135-degree split-point tip reduces walking and lowers required feed force
• Web-thinned tapered web for improved chip clearance and reduced thrust
• Oxide and straw coating reduces friction and provides light corrosion resistance during storage
• Right-hand regular spiral flute for efficient chip evacuation in through and blind holes
• Straight cylindrical shank fits standard 3-jaw drill chucks without adapters
• Meets ANSI and DIN 338 dimensional standards for consistent replacement fitment

Compatibility

Designed as a general-purpose cobalt jobber drill bit for use in any standard drill press or hand drill with a straight-shank chuck sized to accept a 29/64 inch diameter shank. Primary workpiece material codes P, M, K, N, and S indicate suitability for steel, stainless steel, cast iron, non-ferrous metals, and high-temperature alloys.

Installation Notes

Install and remove drill bits with the machine fully powered down and the chuck key removed from the chuck. Secure the shank fully in the chuck jaws and tighten evenly before operation. Use appropriate cutting fluid or coolant when drilling steel to manage heat and extend bit life. Wear ANSI-rated eye protection during all drilling operations.