Precision Twist Drill 5997791 Cobalt Jobber Drill Bit 65

Product Description

The PRECISION TWIST DRILL 5997791 is a cobalt jobber-length drill bit in wire gauge size 65, equivalent to 0.0350 inches in decimal. It features a 135-degree split point with web thinning, which reduces walking on entry and lowers the thrust force needed to start the hole. The straw oxide finish provides mild lubricity and heat resistance during high-speed drilling operations. At 1.5 inches overall length with a 0.625-inch flute length, this is a compact drill designed for small-diameter precision work. It carries NAS 907 and ANSI standards compliance and is classed as a heavy-duty, general-purpose tool suited to machine shop, MRO, and production environments.

This drill bit is intended for drilling operations in steel and a broad range of workpiece materials including ferrous metals, non-ferrous metals, cast materials, and certain superalloys, consistent with its P, M, K, N, and S material group ratings. The straight cylindrical shank fits standard drill chucks in bench drills, drill presses, and CNC machining centers. Its 18xD flute-to-diameter ratio and two-flute regular spiral geometry make it well suited for through-hole and blind-hole drilling in thin stock and small components where tight diameter tolerances are critical.

Key Features

• Wire gauge size 65 (0.0350 inches) cobalt construction for improved hardness and heat resistance over standard HSS
• 135-degree split point with web thinning for self-centering entry and reduced thrust
• Straw oxide coating provides lubricity and mild corrosion resistance
• Two-flute regular spiral geometry with tapered web for efficient chip evacuation
• NAS 907 and ANSI standards compliance for quality assurance in precision applications
• Straight cylindrical shank with zero flats for universal chuck compatibility

Compatibility

Belongs to the R10CO-R15CO-R18CO series. Designed as an OEM-style jobber drill replacement for any standard drill chuck accepting a 0.0350-inch straight shank in production, MRO, or machine shop use.

Installation Notes

Installed by machinists, toolroom technicians, or maintenance professionals using any drill press, CNC machining center, or hand drill with a chuck capable of holding a 0.0350-inch straight shank. Secure the shank fully in the chuck before operation and verify runout when accuracy is critical. Follow shop safety protocols including eye protection and appropriate spindle speeds for cobalt bits in the target workpiece material. Do not use this bit for coolant-through applications as coolant-through capability is not supported on this part.