Precision Twist Drill 5998773 Letter J Jobber Drill Bit

Product Description

The PRECISION TWIST DRILL 5998773 is a jobber-length drill bit sized at letter J (0.2770 inches) designed for general-purpose drilling in a wide range of materials. Built from high-speed steel with a steam oxide coating, it resists heat and friction during extended use. The 135-degree split point reduces walking on entry and lowers the thrust force needed to penetrate hard materials. With an overall length of 4.125 inches and a 2-7/8-inch spiral flute, this bit provides the reach and chip clearance needed for production and maintenance drilling. Licensed machinists, tool-and-die technicians, HVAC fabricators, and maintenance trades install this bit in standard drill presses, hand drills, and CNC setups.

This drill bit is suited for drilling steel, stainless steel, cast iron, non-ferrous metals, superalloys, and titanium. It fits typical production and maintenance applications where a heavy-duty, general-purpose jobber-length bit is required. The straight cylindrical shank accepts standard three-jaw chucks across a wide range of drill drivers and presses. The regular spiral and tapered web with web thinning make it effective across the P, M, K, N, and S workpiece material codes as defined by ISO cutting material classifications. It meets ANSI and NAS 907 standards.

Key Features

• Letter J size at 0.2770 inches diameter for precise hole sizing in metal fabrication and maintenance work
• 135-degree standard point angle reduces center-walking and lowers entry thrust on hard materials
• Steam oxide coating improves lubricity and extends tool life in ferrous materials
• Web-thinned tapered web reduces cutting resistance and improves chip evacuation
• 2-7/8-inch flute length supports a maximum drilling depth of 2.875 inches
• Meets ANSI and NAS 907 standards for heavy-duty jobber-length drill bits

Compatibility

Designed as a general-purpose jobber-length drill bit compatible with any standard three-jaw chuck accepting a 0.2770-inch straight cylindrical shank. Part of the R10B-R15B-R18B series from PRECISION TWIST DRILL.

Installation Notes

Install in a calibrated drill press or hand drill with a properly tightened three-jaw chuck before use. Ensure the workpiece is securely clamped to prevent movement during drilling. Apply cutting fluid when drilling stainless steel, superalloys, or titanium to manage heat and extend bit life. Inspect the cutting edges for wear before each use and replace the bit if the point shows chipping or burnishing.