Precision Twist Drill 5999804 Extra Length Drill Bit Hss

Product Description

The PRECISION TWIST DRILL 5999804 is a high speed steel extra length drill bit designed for deep-hole drilling in a wide range of materials. Built to Series 1290 specifications, it features a 0.5781-inch diameter, a 12-inch overall length, and a 9-inch spiral flute length, giving it a reach well beyond standard jobber-length bits. The 118-degree point angle and web-thinned, tapered web construction reduce entry force and improve chip clearance. The uncoated HSS construction is well suited for general-purpose production and maintenance drilling where consistent performance across varied materials is the priority.

This bit is intended for applications requiring extended reach into deep bores, stepped assemblies, or fixtures where a standard-length bit cannot reach the workpiece. The straight-cylindrical shank is compatible with standard drill chucks used in drill presses, milling machines, and hand-held industrial drills. Cutting direction is right-hand with a regular spiral, making it appropriate for conventional drilling setups. Primary workpiece materials include aluminum, magnesium, copper, nickel, synthetic materials, and titanium. Secondary workpiece materials include stainless steel, hardened steel, nickel alloys, malleable iron, high strength bronze, magnesium alloys, and reinforced plastics.

Key Features

• 0.5781-inch diameter with matching straight-cylindrical shank diameter for secure chuck engagement
• 12-inch overall length and 9-inch flute length for extended-reach drilling — a 12xD flute-to-diameter ratio
• 118-degree standard point angle with web thinning for reduced thrust and easier starting
• Two-flute regular spiral design promotes efficient chip evacuation in deep holes
• Uncoated high speed steel construction — resharpenable and suitable for general-purpose use across multiple material groups
• Meets ANSI standards; Series 1290 general-purpose grade

Compatibility

Designed as a general-purpose extra length drill bit compatible with standard drill chucks accepting a 0.5781-inch straight-cylindrical shank, for use in drill presses, milling machines, and industrial hand drills.

Installation Notes

Secure the straight-cylindrical shank firmly in a drill chuck rated for the shank diameter before operating. Ensure the machine spindle speed is appropriate for the workpiece material and bit diameter — consult published HSS speed-and-feed charts for the specific material being drilled. Use cutting fluid or coolant as appropriate for the workpiece material, even though this bit does not have through-coolant capability. Inspect the cutting edges before each use and resharpen or replace the bit if chipping or dulling is observed.