Precision Twist Drill 5999377 Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5999377 is a screw machine length drill bit designed for high-performance drilling in demanding trade and industrial applications. Built from high speed steel (HSS) with a coated finish, this bit features a 135-degree split point and web-thinned, tapered web configuration that reduces walking and lowers thrust force at the start of a cut. At 0.272 inches (letter size I) in diameter with an overall length of 2-11/16 inches and a flute length of 1-1/2 inches, it is sized for use in screw machines, CNC lathes, and short-travel drilling setups. The right-hand spiral flute and straight-cylindrical shank make it compatible with standard drill chucks and collet holders.

This bit is rated for heavy-duty use and is optimized for primary workpiece material of titanium, as well as similarly difficult-to-machine metals encountered in precision machining environments. The screw machine length format provides greater rigidity than jobber-length bits, making it well suited for high-production drilling where runout control and hole-position accuracy are critical. It is commonly used by machinists, tool and die technicians, and maintenance professionals running production or repair operations on metal components.

Key Features

• 0.272 inch diameter, letter size I, for precise hole sizing
• 135-degree split point with web thinning reduces thrust and eliminates center punch requirement
• High speed steel construction with coated finish for extended tool life
• Screw machine length body at 2-11/16 inches overall provides added rigidity over jobber-length bits
• Right-hand cut, regular spiral flute for efficient chip evacuation
• Flute-to-diameter ratio of 2.5xD suits moderate-depth hole applications
• Meets ANSI and NAS 907 specifications for dimensional and performance standards

Compatibility

Designed as an OEM-style replacement and standard production drill bit for use in screw machines, CNC turning centers, and drill presses accepting straight-cylindrical shanks. Primary workpiece material rating is titanium per series R42C specifications.

Installation Notes

Installation and use of this drill bit should be performed by qualified machinists or maintenance technicians familiar with rotating cutting tools. Ensure the machine spindle is fully stopped and locked out before inserting or removing the bit from the chuck or collet. Verify chuck capacity and collet size are appropriate for the 0.272 inch straight shank before engaging the spindle. Follow applicable shop safety standards and manufacturer feed-and-speed guidelines for the workpiece material being drilled.