Precision Twist Drill 5998570 Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5998570 is a screw machine length high speed steel drill bit designed for short-hole drilling applications where rigidity and reduced runout matter. Built to ANSI standards, this 0.5 inch diameter bit features a 118-degree standard point angle, a right-hand spiral flute, and a straight-cylindrical shank. The web-thinned, tapered web configuration reduces thrust force at entry and improves chip evacuation. At 3.75 inches overall length with a 2.25-inch flute length, it fits most standard drill chucks and drill presses without extended reach adapters. Machinists, tool-and-die techs, and maintenance trades install this type of bit for production drilling in metalworking and general fabrication environments.

This bit is rated for use in high-performance general-purpose applications with titanium listed as the primary workpiece material. The bright uncoated finish keeps the tool true to its ground tolerances without added coating thickness, which is preferred when drilling softer or gummy metals where coatings can load up. The Series R40 designation identifies the product line within the PRECISION TWIST DRILL catalog. The 2.5xD flute-to-diameter ratio provides adequate chip clearance for short-hole work without sacrificing body stiffness.

Key Features

• 0.5 inch diameter, screw machine length for reduced deflection and improved hole location accuracy
• 118-degree standard point angle suitable for general-purpose metal drilling
• Web-thinned tapered web reduces thrust and improves penetration in harder materials
• Bright uncoated HSS finish maintains ground tolerances and suits a broad range of workpiece materials
• Right-hand cut, spiral flute for positive chip evacuation
• Conforms to ANSI standards, Series R40

Compatibility

Designed as an OEM-style replacement and general-use drill bit for standard drill chucks accepting straight-cylindrical shanks in the 0.5 inch diameter range.

Installation Notes

This bit is installed by machinists and maintenance technicians in drill presses, lathes, or hand-held power drills equipped with a compatible chuck. Secure the shank fully in the chuck and verify concentricity before operation. Use appropriate cutting fluid or coolant for the workpiece material, and never exceed the recommended RPM for the bit diameter and material combination. Inspect the cutting edges before each use and replace the bit if chipping or excessive wear is present.