Precision Twist Drill 5999839 No. 43 Hss Jobber Drill Bit

Product Description

The PRECISION TWIST DRILL 5999839 is a No. 43 wire-size jobber-length drill bit manufactured from high speed steel with an oxide/bronze coating. It measures 0.0890 inches in diameter and 2.25 inches overall, with a 5/8-inch flute length and a 135-degree split point that reduces walking on entry and lowers thrust force compared to a conventional 118-degree point. The web-thinned, tapered-web construction improves chip evacuation. This bit ships individually and is sold in multiples of 12. It suits machine shops, maintenance technicians, and field tradespeople who drill in tight or precision-tolerance situations.

The 5999839 is built for general-purpose drilling in a broad range of materials including steel, stainless steel, cast iron, non-ferrous metals, superalloys, and titanium. The regular-spiral, two-flute design with a straight cylindrical shank fits standard drill chucks and drill press spindles. With a 7xD flute-to-diameter ratio and a maximum drilling depth of 5/8 inch, it is well suited to through-hole and shallow blind-hole applications in both production and maintenance environments.

Key Features

• No. 43 wire size — 0.0890-inch diameter for close-tolerance hole sizing
• 135-degree split point reduces thrust and minimizes bit walking on hard or smooth surfaces
• High speed steel construction with oxide/bronze coating for heat and wear resistance
• Web-thinned, tapered web design promotes efficient chip evacuation
• Two-flute regular spiral compatible with standard straight-shank chucks
• Meets NAS 907 specification for dimensional and material consistency

Compatibility

Designed as a general-purpose jobber-length drill bit compatible with any standard drill chuck or drill press accepting a 0.0890-inch straight cylindrical shank. Part of the PRECISION TWIST DRILL Series R88CO-R89CO.

Installation Notes

Installation and use should be performed by qualified machinists or tradespeople familiar with rotating cutting tools. Secure the workpiece firmly before drilling and confirm the chuck is fully tightened on the shank before powering the spindle. Wear appropriate eye protection and never exceed the rated speed for the bit diameter and material combination being drilled. Inspect the cutting edges before each use and replace the bit if chipping or excessive wear is observed.