Precision Twist Drill 5998550 Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5998550 is a screw machine length drill bit engineered for high-performance drilling in demanding trade and industrial applications. Built from high speed steel with a coated finish, this bit measures 0.12 inches (wire size #31) in diameter with an overall length of 1-7/8 inches and a flute length of 7/8 inch. The 135-degree split point angle and web-thinned, tapered web configuration reduce walking and improve penetration on entry. Right-hand spiral flute geometry clears chips efficiently. Licensed machinists, tool-and-die tradespeople, and maintenance mechanics commonly specify this bit for precision hole-making in tight quarters.

This bit is rated for primary use in titanium workpieces and is classified as heavy duty grade within the R41C series. Its screw machine (stub) length provides added rigidity compared to jobber-length bits, making it well suited for drill press work, CNC operations, and hand-drill applications where deflection must be minimized. The 2.5xD flute-to-diameter ratio and regular spiral type support consistent chip evacuation in both through-hole and blind-hole scenarios. It meets ANSI and NAS 907 standards.

Key Features

• 135-degree split point angle with web thinning reduces thrust and walking on entry
• High speed steel construction with coated finish for extended tool life
• Screw machine (stub) length adds rigidity and reduces deflection
• Right-hand cut with regular spiral flute for efficient chip removal
• Meets ANSI and NAS 907 standards for heavy duty performance
• No coolant-through requirement — compatible with standard dry or flood-coolant setups

Compatibility

Designed as a heavy-duty OEM-style replacement or new-installation drill bit for use in titanium and similar high-strength materials; part of the PRECISION TWIST DRILL R41C series covering the 0.1000 to 0.1500 inch diameter range.

Installation Notes

Installation and use should be performed by qualified machinists or trade professionals familiar with proper drilling speeds and feeds for the workpiece material. Secure the workpiece and verify spindle alignment before operation. Always wear appropriate eye protection and ensure the bit is fully seated and tightened in the chuck or collet before starting the machine. Do not exceed recommended surface footage for the workpiece material or coating type.