Precision Twist Drill 5999389 Jobber Drill Bit 0.025 in Hss

Product Description

The PRECISION TWIST DRILL 5999389 is a jobber-length drill bit designed for general-purpose drilling in metal and cast iron. Built from high speed steel (HSS) with a bright, uncoated finish, it features a standard 118-degree point angle and a right-hand spiral flute that clears chips efficiently during through-hole drilling. The straight-cylindrical shank seats securely in standard drill chucks. At 0.025 inches in diameter, this wire-gauge size 72 bit handles small-diameter work where precision entry is critical. Machinists, tool-and-die workers, and maintenance technicians reach for this bit when drilling pilot holes, clearance holes, or small through-holes in steel and cast iron workpieces.

This bit is suited for use in benchtop drill presses, CNC machining centers, and hand-held power drills equipped with a chuck capable of holding a straight shank at this diameter. Its general-purpose grade and ANSI-standard geometry make it a reliable choice for light-duty production and maintenance drilling applications in steel and cast iron. No coolant-through capability is present, so external cutting fluid or dry operation is typical for this size. Sold individually, with a minimum order quantity of 12 units per order.

Key Features

• Wire gauge size 72 at 0.025 inches diameter for small-diameter precision drilling
• 118-degree standard point angle with web-thinned, tapered web for reduced entry force
• High speed steel construction for durability in steel and cast iron
• Bright uncoated finish — no coating to flake or build up in tight clearances
• Right-hand cut with regular spiral flute for efficient chip evacuation
• ANSI-standard geometry; Series R18P general-purpose grade

Compatibility

Designed as a general-purpose jobber-length drill bit compatible with any standard drill chuck or collet system capable of accepting a straight-cylindrical shank at 0.025 inches diameter. Primary workpiece materials are steel and cast iron.

Installation Notes

A licensed machinist or maintenance technician should secure the bit firmly in the chuck before operation, verifying zero runout at this small diameter to prevent breakage. Always reduce spindle speed and feed rate appropriately for small-diameter HSS bits in hard materials. Apply external cutting fluid when drilling steel to extend tool life. Inspect the cutting edges before each use — at 0.025 inches diameter, edge chipping is not always visible without magnification.