Precision Twist Drill 5997451 Taper Length Drill Bit

Product Description

The PRECISION TWIST DRILL 5997451 is a taper length high speed steel drill bit from the QC91P series, designed for professionals who need extended reach beyond standard jobber-length drills without sacrificing rigidity. The bit measures 9/64 inch (0.1406 inch decimal) in diameter with a 3 inch flute length and an overall length of 5-3/8 inches, giving a 6xD flute-to-diameter ratio. The 135-degree split point geometry self-centers on contact, reducing walking and the need for a center punch. Right-hand cut with a parabolic flute profile, it is built for heavy-duty general-purpose drilling across a wide range of materials. The bright, uncoated HSS finish suits applications where coating compatibility or regrinding is a factor.

This bit is suited for use in machine shop, fabrication, maintenance, and field service environments where a straight-shank taper length bit is required. The parabolic flute geometry promotes efficient chip evacuation during deeper hole applications, reducing heat buildup and bit deflection. It is a practical choice for drilling operations in alloy steel, carbon steel, stainless steel, cast iron, aluminum, brass, bronze, copper, titanium, magnesium, nickel, graphite, and related alloys where extended flute length improves access and chip clearance.

Key Features

• 135-degree split point self-centers on entry, minimizing workpiece marking and bit walking
• Parabolic flute profile enhances chip evacuation in deeper holes
• Taper length body at 5-3/8 inches OAL provides extended reach versus standard jobber bits
• High speed steel (HSS) construction with bright/uncoated finish for general-purpose and regrindable applications
• Web-thinned, tapered web configuration reduces cutting resistance and thrust requirements
• Straight cylindrical shank compatible with standard drill chucks; no threaded shank or coolant-through requirement
• Conforms to ANSI standards; heavy-duty grade rating for demanding drilling cycles

Compatibility

Designed as a general-purpose taper length drill bit compatible with standard straight-shank drill chucks and drilling equipment sized for 9/64 inch shanks. Suitable for drilling alloy steel, aluminum, aluminum alloy, brass, bronze, carbon steel, cast iron, copper, graphite, hardened steel, magnesium, magnesium alloy, malleable iron, nickel, stainless steel, steel, tempered steel, titanium, and titanium alloy workpieces.

Installation Notes

This bit is installed by machinists, toolroom technicians, and maintenance tradespeople using standard drill presses, CNC drilling centers, or handheld drilling equipment. Secure the straight shank firmly in the drill chuck before operation and verify runout is within acceptable limits to prevent premature wear. Always reduce feed rate when breaking through the back side of a workpiece to avoid grabbing. Use appropriate cutting fluid or coolant for the workpiece material to extend bit life, particularly when drilling steel or stainless.