Precision Twist Drill 5999880 Extra Length Drill Bit

Product Description

The PRECISION TWIST DRILL 5999880 is a 5/16 inch diameter extra length high-speed steel drill bit designed for deep-hole drilling applications where standard-length bits fall short. Built to ANSI standards, it features a 118-degree standard point angle with web thinning for reduced thrust on entry, and a bright uncoated finish suited for general-purpose material removal. The spiral flute geometry promotes efficient chip evacuation in deeper bores. With a 12 inch overall length and a 9 inch flute length, this bit gives machinists, maintenance techs, and fabricators extended reach in confined or deep workpieces without sacrificing rigidity.

This bit is used in general-purpose drilling across a wide range of materials including aluminum, magnesium, copper, nickel, titanium, stainless steel, malleable iron, hardened steel, high-strength bronze, nickel alloys, and reinforced plastics. It suits production and maintenance environments where a long-reach drill is needed to clear structural members, reach recessed bosses, or drill through thick-section assemblies. The straight cylindrical shank accepts standard drill chucks and collet holders common in most shop and field setups.

Key Features

• 5/16 inch diameter with matching 5/16 inch straight cylindrical shank for direct chuck mounting
• 12 inch overall length and 9 inch flute length for deep-reach drilling applications
• 118-degree standard point angle with web thinning for reduced entry thrust
• High-speed steel construction with bright uncoated finish for general-purpose use
• 2-flute right-hand spiral design with tapered web for efficient chip clearing
• Meets ANSI standards, Series 1290 general-purpose grade

Compatibility

Designed as a general-purpose extra length drill bit compatible with aluminum, magnesium, copper, nickel, titanium, stainless steel, malleable iron, hardened steel, high-strength bronze, nickel alloys, and reinforced plastic materials. Fits any standard drill chuck or collet holder accepting a 5/16 inch straight cylindrical shank.

Installation Notes

Installation and use should be performed by qualified machinists or maintenance technicians familiar with drilling operations and machine tool safety. Always secure the workpiece fully before drilling and confirm the chuck or collet is torqued to the equipment manufacturer specification. Reduce feed pressure when the bit breaks through the exit face to avoid workpiece damage or bit deflection. Inspect the cutting edges for wear before each use, particularly when drilling harder secondary materials such as stainless steel or hardened steel.