Precision Twist Drill 5999785 Cobalt Drill Bit 13

Product Description

The PRECISION TWIST DRILL 5999785 is a cobalt jobber length drill bit in wire gauge size 13, equivalent to 0.1850 inches decimal diameter. Built on the R88CO-R89CO series platform, it features a 135-degree split point angle and a web-thinned, tapered web construction that reduces thrust and improves centering on entry. The straight-cylindrical shank measures 0.1850 inches in diameter and 2.375 inches in length. Overall length is 3.5 inches. With 2 spiral flutes and a right-hand cut, this bit is suited for production and maintenance drilling in demanding materials. It meets NAS 907 specification. Each unit weighs approximately 0.04 pounds.

This drill bit is intended for use on steel, stainless steel, cast iron, non-ferrous metals, superalloys, and titanium. The cobalt high-speed steel construction makes it appropriate for harder and heat-generating workpiece materials where standard HSS bits lose their edge prematurely. It is used in drill press, hand drill, and CNC operations by machinists, maintenance technicians, and fabricators. The 6xD flute-to-diameter ratio and 1.125-inch maximum drilling depth suit it for through-holes and blind holes in plate stock and structural material of typical jobber-depth applications.

Key Features

• Wire size 13 (0.1850 inches decimal) cobalt high-speed steel construction for heat and wear resistance
• 135-degree split point with web thinning reduces walking and lowers entry thrust
• Right-hand spiral flute with tapered web configuration for efficient chip evacuation
• 3.5-inch overall length with 1.125-inch flute length and 2.375-inch shank length
• Meets NAS 907 specification for aerospace and industrial drilling applications
• Compatible with P, M, K, N, and S material classification workpieces including superalloys and titanium

Compatibility

Designed as an OEM-style replacement or direct-fit jobber length drill bit for use in standard straight-shank drill chucks across drill presses, hand drills, and CNC equipment requiring a wire size 13 (0.1850-inch) bit in the R88CO-R89CO series.

Installation Notes

This bit is installed by machinists and maintenance technicians in any tool holder accepting a straight-cylindrical shank of 0.1850 inches. Ensure the drill chuck is fully tightened and the workpiece is securely fixtured before operation. Use appropriate cutting fluid when drilling stainless steel, superalloys, or titanium to preserve edge life. Inspect the cutting edges for wear or chipping before each use; do not run a damaged bit.