Precision Twist Drill 5998839 Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5998839 is a screw machine length drill bit designed for high-performance drilling in metal fabrication and machining applications. Built from high speed steel (HSS) with a bright uncoated finish, this bit features a 118-degree standard point angle and a web-thinned, tapered web configuration that reduces thrust and improves chip evacuation. The straight-cylindrical shank measures 0.1495 inches in diameter, corresponding to wire gauge size 25. Right-hand spiral flutes and a 2.5xD flute-to-diameter ratio provide consistent chip removal during through-hole and blind-hole drilling operations. Licensed machinists and tool-and-die technicians are the primary installers of this bit in production environments.

The 5998839 is suited for screw machine operations, CNC drilling programs, and manual drill press use where short, rigid tooling is required to minimize deflection. Its overall length of 2-1/16 inches and flute length of 1 inch make it well matched to high-cycle production drilling in close-tolerance work. The primary workpiece material rating is titanium, though the general-purpose grade supports use across a broad range of metals and alloys common in machining shops. The bit conforms to ANSI standards and is sold individually with a minimum order quantity of 12 units.

Key Features

• 0.1495 inch diameter, wire gauge size 25, for precise hole sizing
• 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
• Screw machine length (2-1/16 inches overall) provides rigidity and minimizes runout
• Right-hand spiral flutes with 2.5xD ratio promote efficient chip clearance
• Bright uncoated finish; ANSI-compliant Series R41

Compatibility

Designed as an OEM-style replacement or production-supply drill bit for screw machine and drill press applications requiring wire gauge size 25 tooling in ANSI-standard straight-shank chucks.

Installation Notes

Installation is performed by machinists or tool-room technicians. Secure the straight-cylindrical shank fully in a compatible drill chuck or collet before operation, and verify chuck runout is within acceptable tolerance to preserve hole accuracy. Ensure the workpiece is properly fixtured and that the machine spindle is at a full stop before changing or inspecting the bit. Follow the machine tool manufacturer guidelines and applicable shop safety codes when selecting feed rate and spindle speed for the target material.