Precision Twist Drill 5998970 Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5998970 is a screw machine length drill bit engineered for high-performance drilling in metal fabrication and machining applications. Built from high speed steel with a bright/uncoated finish, this bit features a 0.397-inch diameter, a 118-degree standard point angle, and a web-thinned tapered web configuration for improved penetration and reduced thrust. The straight-cylindrical shank ensures secure seating in standard drill chucks and machine spindles. At 3-5/16 inches overall length with a 1-15/16-inch flute length, the screw machine format is designed for rigid, close-tolerance work where a shorter body reduces deflection and increases rigidity.

This bit is suited for use in CNC machining centers, drill presses, and manual screw machines operating on ferrous and non-ferrous stock. The Series R42 designation places it in a general-purpose high-performance line rated for drilling titanium and similarly demanding primary workpiece materials. The 2.5xD flute-to-diameter ratio supports efficient chip evacuation in shorter hole depths typical of screw machine work. ANSI standards compliance confirms dimensional accuracy for interchangeable use across compatible tooling setups.

Key Features

• 0.397-inch (Letter X) diameter with ANSI-compliant dimensional accuracy
• 118-degree standard point angle with web-thinned tapered web for reduced entry thrust
• High speed steel construction rated for titanium and general-purpose metal drilling
• Bright/uncoated finish suitable for use with cutting fluids
• Screw machine length body minimizes deflection in rigid setups
• Right-hand spiral flute with 2.5xD flute ratio for efficient chip removal

Compatibility

Designed as an OEM-style replacement and standard-use drill bit for screw machine length applications within the 0.3500 to 0.4000 inch diameter range, fitting standard straight-shank drill chucks and machine spindles.

Installation Notes

Machinist or CNC operator installation. Secure the straight-cylindrical shank fully into the chuck or collet before operation and verify runout before cutting. Power down and de-energize the machine spindle completely before changing bits. Follow shop safety protocols and applicable ANSI machining standards when operating at speed in hard materials such as titanium.