Precision Twist Drill 5999795 Jobber Drill Bit 21

Product Description

The PRECISION TWIST DRILL 5999795 is a jobber-length drill bit in wire gauge size 21, equivalent to 0.1590 inches in diameter. Built from high-speed steel with a cobalt oxide bronze coating, it is designed for general-purpose drilling in demanding materials. The 135-degree split point reduces walking and allows faster entry without a center punch. Overall length is 3.25 inches with a 1.0625-inch flute length. The straight cylindrical shank seats securely in standard drill chucks. This bit suits machinists, maintenance technicians, and metalworking professionals who need consistent performance across a range of workpiece materials.

This drill bit is well-suited for drilling steel, stainless steel, cast iron, non-ferrous metals, superalloys, and titanium in both shop and field environments. It fits production drilling, maintenance repair, and fabrication work where wire-gauge sizing is specified. The 7xD flute-to-diameter ratio provides adequate chip clearance in typical jobber-length applications. The web-thinned, tapered web construction reduces thrust and improves cutting efficiency in harder materials. It meets NAS 907 specification requirements, making it appropriate for aerospace and precision manufacturing environments where dimensional standards are enforced.

Key Features

• Wire gauge size 21, 0.1590 inches decimal diameter
• 135-degree standard split point reduces drill walking and center-punch need
• High-speed steel construction with cobalt oxide bronze coating for heat and wear resistance
• Web-thinned tapered web reduces cutting thrust in hard and tough materials
• Right-hand spiral flute with 1.0625-inch maximum drilling depth
• Meets NAS 907 specification for precision and aerospace applications

Compatibility

Designed as a general-purpose jobber-length drill bit compatible with any standard drill chuck accepting a 0.1590-inch straight cylindrical shank. Part of the R88CO-R89CO series from PRECISION TWIST DRILL.

Installation Notes

Install in a standard drill chuck, keyed or keyless, and confirm shank is fully seated before use. Power down the drill press or disconnect the handheld tool before changing bits. Use appropriate cutting fluid or coolant when drilling stainless steel, superalloys, or titanium to extend tool life and maintain dimensional accuracy. Verify workpiece is securely clamped before drilling to prevent movement and bit breakage.