Precision Twist Drill 5999409 Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5999409 is a screw machine length drill bit designed for high-performance metal drilling applications. Built from high speed steel with a coated finish, this bit features a 135-degree split point and web-thinned, tapered web construction that reduces walking and improves hole entry accuracy. The straight-cylindrical shank measures 0.125 inches in diameter, with an overall length of 1.875 inches and a flute length of 0.875 inches. Rated as a heavy duty tool and compliant with ANSI and NAS 907 standards, this bit is suited for precision drilling in demanding shop and field environments. Machinists, tool and die technicians, and mechanical contractors working with close-tolerance assemblies will find this a reliable workhorse for stub-length drilling tasks.

The 5999409 is purpose-built for screw machine length drilling where a shorter, stiffer bit is required to maintain positional accuracy. Its primary rated workpiece material is titanium, making it appropriate for aerospace, defense, and precision manufacturing applications where conventional bits underperform. The 2.5xD flute-to-diameter ratio and regular spiral flute geometry support efficient chip evacuation in deep or repeated-hole drilling scenarios. Coolant-through capability is not included in this design.

Key Features

• 0.125-inch diameter with 1.875-inch overall length for compact, rigid stub-length drilling
• 135-degree split point reduces thrust force and minimizes bit walking on entry
• Web-thinned, tapered web construction improves penetration in hard and exotic materials
• High speed steel construction with coated finish for extended tool life
• Right-hand cut with regular spiral flute for consistent chip evacuation
• Meets ANSI and NAS 907 specifications for dimensional and performance compliance

Compatibility

Designed as a screw machine length replacement or production drill bit within the R40C series, covering the 0.1000 to 0.1500 inch decimal inch size range. Primary rated workpiece material is titanium; also suited for general ferrous and non-ferrous metals in precision machining applications.

Installation Notes

Installation and use of this drill bit should be performed by machinists or qualified trades personnel familiar with proper chuck seating and speed-feed selection for the workpiece material. Secure the straight-cylindrical shank firmly in the drill chuck or collet before operation to prevent slippage. Select spindle speed appropriate to the workpiece material and bit diameter per standard machining references. Inspect the cutting edges before each use and replace the bit if chipping or wear is detected.