Precision Twist Drill 5999056 Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5999056 is a screw machine length drill bit designed for high-performance drilling in demanding trade and industrial applications. Built from high speed steel with a coated finish, this bit features a 135-degree split point and web-thinned, tapered web construction that reduces thrust and improves self-centering at the start of a cut. It measures 0.397 inches in diameter with an overall length of 3-5/16 inches and a flute length of 1-15/16 inches. The straight-cylindrical shank fits standard drill chucks without adapters. This is a right-hand cut, spiral flute bit rated for heavy-duty use and engineered to meet ANSI and NAS 907 specifications.

This bit is specified for drilling titanium as its primary workpiece material, making it a go-to for aerospace, medical fabrication, and precision machining environments where titanium and other work-hardening alloys are common. The screw machine length profile — shorter than jobber length — provides added rigidity and reduced deflection when used in drill presses, CNC machining centers, and turret lathes. The 2.5xD flute-to-diameter ratio supports chip evacuation in deep-hole applications. Machinists, tool-and-die technicians, and industrial maintenance trades working with hard materials will find this bit suited for production and repair work alike.

Key Features

• 135-degree split point reduces walking and decreases required feed force on hard materials
• Web-thinned, tapered web construction improves cutting efficiency and lowers heat buildup
• High speed steel with coated finish extends tool life in abrasive and work-hardening materials
• Screw machine length body provides greater rigidity and reduced deflection versus jobber bits
• Right-hand spiral flute promotes efficient chip clearance during drilling
• Meets ANSI and NAS 907 standards for dimensional and performance consistency

Compatibility

Designed for use in standard drill chucks accepting straight-cylindrical shanks. Rated for drilling titanium per Series R42C specifications; suitable for other hard and work-hardening alloys in applications requiring a heavy-duty, short-length bit within the 0.3500 to 0.4000 inch diameter range.

Installation Notes

Install into a properly rated drill chuck and verify shank seating before operation. Use appropriate cutting fluid or coolant when drilling titanium to manage heat and extend tool life. Operate at speeds and feeds appropriate for titanium and high-strength alloys — consult published machining data for the specific workpiece material. Inspect the cutting edges for wear or chipping before each use and remove from service if damage is observed.