Precision Twist Drill 5998647 Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5998647 is a screw machine length drill bit in wire size 55, designed for high-performance drilling in tight, close-tolerance applications. Built from high-speed steel with a coated finish, the bit features a 135-degree split point angle and web-thinned geometry that reduces walking and improves entry accuracy. The straight-cylindrical shank measures 0.0520 inches in diameter, matching the bit diameter for easy chuck seating. At 1-5/8 inches overall length, this stub-length format provides added rigidity over jobber-length bits, making it well-suited for use in drill presses, screw machines, and CNC turret setups. Machinist and tool-and-die professionals are the primary users of this format.

This bit is engineered for drilling titanium as its primary workpiece material, which demands high-performance tooling with appropriate geometry and surface treatment. The screw machine length format is common in production environments where short, rigid bits minimize deflection during high-cycle operations. The R41C series follows ANSI and NAS 907 standards, making it appropriate for aerospace and precision manufacturing environments where specification compliance is required. The 5/8-inch flute length with a 2.5xD flute-to-diameter ratio supports chip evacuation in shallow-depth drilling passes.

Key Features

• Wire size 55 (0.0520 inches) straight-cylindrical shank for standard chuck compatibility
• 135-degree point angle with web thinning reduces thrust and prevents bit walking
• High-speed steel construction with coated finish for extended tool life in hard materials
• Screw machine length (1-5/8 inches OAL) provides rigidity over standard jobber-length bits
• Meets ANSI and NAS 907 specifications for use in aerospace and precision machining
• Regular spiral, tapered web configuration optimized for titanium and similar alloys

Compatibility

Designed for use in screw machines, drill presses, and CNC turret setups requiring wire size 55 stub-length tooling. Primary workpiece material is titanium per specification designation ANSI and NAS 907.

Installation Notes

Install this bit into a compatible chuck or collet rated for 0.0520-inch straight-cylindrical shanks, ensuring full shank engagement before tightening. Secure the workpiece firmly before drilling to prevent movement during high-cycle operations. Use appropriate cutting fluid for titanium to manage heat buildup and extend tool life. Replace the bit at the first sign of point degradation to avoid workpiece damage and tolerance loss.