Precision Twist Drill 5999135 No. 31 Hss Jobber Drill Bit

Product Description

The PRECISION TWIST DRILL 5999135 is a jobber-length twist drill bit designed for general-purpose drilling in a wide range of metal and hard materials. Ground from high-speed steel (HSS) with a steam oxide coating, this bit measures 0.1200 inches in diameter (wire size No. 31) and carries a 135-degree split-point tip geometry. The 135-degree point reduces walking on entry and requires less thrust than a standard 118-degree point, making it well suited for production and maintenance drilling. Overall length is 2.75 inches, with a 1.625-inch spiral flute and a straight cylindrical shank. It is sized to NAS 907 and ANSI standards and is classified as heavy-duty grade. Licensed trades and shop technicians working in steel fabrication, HVAC equipment assembly, and mechanical service install this bit in standard drill chucks without modification.

This drill bit is intended for use on steel, stainless steel, cast iron, non-ferrous metals, superalloys, and titanium. Its regular spiral and tapered web with web thinning make it effective across a broad range of workpiece hardnesses. Typical applications include hole drilling in sheet metal, structural steel, pipe flanges, HVAC equipment panels, and general mechanical assemblies where a consistent, accurate hole diameter of 0.1200 inches is required. The bit is suited for both hand-held drill and drill-press operations.

Key Features

• Wire size No. 31, 0.1200-inch diameter for precise hole sizing
• 135-degree split-point tip reduces entry walking and required thrust force
• High-speed steel construction with steam oxide coating for lubricity and basic corrosion resistance
• Web-thinned, tapered web design improves chip evacuation and reduces heat buildup
• Right-hand cut with 2-flute regular spiral for efficient material removal
• Meets NAS 907 and ANSI standards; rated for steel, stainless steel, cast iron, non-ferrous metals, superalloys, and titanium

Compatibility

Designed as an OEM-style general-purpose jobber drill bit for use in any standard drill chuck accepting a straight cylindrical shank at 0.1200 inches diameter. Part of the Series R10B, R15B, and R18B family per supplier specification.

Installation Notes

This bit is installed and operated by machinists, maintenance technicians, pipefitters, HVAC mechanics, and other trades using standard drill presses or hand-held power drills. Secure the straight shank fully in the chuck before operation and confirm chuck is properly tightened. Use appropriate cutting fluid or lubricant when drilling stainless steel, superalloys, or titanium to extend bit life and manage heat. Inspect the cutting edges before use and replace the bit if chipping or wear is evident to maintain hole quality and prevent workpiece damage.