Precision Twist Drill 5998002 Taper Length Drill Bit

Product Description

The PRECISION TWIST DRILL 5998002 is a taper length, high speed steel (HSS) drill bit in wire size No. 21, equivalent to 0.1590 inches in diameter. It features a 135-degree split point that reduces walking on entry and a parabolic flute profile that improves chip evacuation at depth. The straight cylindrical shank is compatible with standard drill chucks. Intended for use by machinists, maintenance technicians, and metalworking tradespeople, this bit handles general-purpose drilling in a wide range of metals and alloys. Overall length is 5-3/4 inches with a 3-3/8 inch flute length, giving it the reach needed for deeper hole applications where a jobber-length bit falls short.

This drill bit is suited for production and maintenance drilling in metal fabrication shops, HVAC equipment manufacturing, mechanical contracting, and general industrial environments. The parabolic flute geometry and web-thinned split point make it effective in materials that generate long, stringy chips. It can be run in benchtop drill presses, magnetic-base drills, CNC machining centers, and handheld electric drills where straight-shank tooling is appropriate.

Key Features

• Wire size No. 21 — 0.1590 inch diameter for precise hole sizing in standard wire-gauge applications
• 135-degree split point reduces thrust force and eliminates the need for a center punch on most metals
• Parabolic flute profile promotes fast chip clearing in deep holes, reducing heat buildup
• Web-thinned, tapered web construction for lower cutting resistance across the full flute length
• Taper length body — 5-3/4 inches OAL and 3-3/8 inch flute — reaches beyond standard jobber-length capacity
• Bright/uncoated HSS finish; compatible with cutting oils and coolants where the machine setup permits
• Meets ANSI standards; heavy-duty grade construction for repeated use in production environments

Compatibility

Designed as a general-purpose taper length drill bit for use in 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. Fits any standard drill chuck accepting a 0.1590-inch straight cylindrical shank.

Installation Notes

Installation and use of this bit should be performed by qualified machinists or tradespeople familiar with drill press or power-tool safety practices. Secure the workpiece firmly before drilling and ensure the chuck is fully tightened on the shank before starting the spindle. Select an appropriate feed rate and spindle speed for the workpiece material — refer to published HSS cutting-speed charts for guidance. Apply a suitable cutting fluid when drilling ferrous metals or stainless steel to extend tool life and improve hole finish.