Precision Twist Drill 5998831 Drill Bit Letter O Hss

Product Description

The PRECISION TWIST DRILL 5998831 is a jobber length drill bit sized to Letter O (0.3160 inches decimal equivalent) designed for general-purpose hole-making in metalworking applications. Built from high speed steel with a steam oxide coating, this bit features a 118-degree standard point angle, a tapered web with web thinning for improved chip clearance, and a right-hand spiral flute configuration. Overall length is 4.5 inches with a flute length of 3.1875 inches, giving it the reach and chip evacuation capacity typical of ANSI-spec jobber series bits. Licensed HVAC technicians, machinists, pipefitters, and maintenance trades reach for jobber bits like this when drilling through ferrous and non-ferrous stock in production or field settings.

This bit is suited for drilling steel, stainless steel, cast iron, non-ferrous metals, superalloys, and titanium. It fits standard drill chucks accepting a straight-cylindrical shank of 0.3160 inches. The regular spiral and 10xD flute-to-diameter ratio make it effective for through-hole and blind-hole work in sheet metal, plate, and structural members. It ships as a single unit and carries no coolant-through capability, so external cooling or cutting fluid applied at the point is recommended when drilling harder materials.

Key Features

• Letter O size — 0.3160 inch decimal equivalent for precise hole sizing
• High speed steel construction with steam oxide coating for lubricity and mild corrosion resistance
• 118-degree standard point angle for general-purpose entry in a wide range of metals
• Tapered web with web thinning reduces thrust and improves chip flow
• Right-hand cut, regular spiral, 2-flute design for efficient material removal
• Straight-cylindrical shank fits standard 3-jaw and keyed drill chucks without adapters

Compatibility

Designed as an OEM-style general-purpose jobber drill bit compatible with any drill press, hand drill, or CNC machine tool accepting a straight-cylindrical shank of 0.3160 inches. Conforms to ANSI specification standards per Series R10-R15-R18.

Installation Notes

This drill bit is installed by machinists, maintenance mechanics, pipefitters, and general trade professionals using standard drill chucks. Secure the shank fully in the chuck before operation and verify the workpiece is clamped or fixtured to prevent rotation. Apply cutting fluid or a suitable coolant to the cutting point when drilling stainless steel, superalloys, or titanium to extend tool life and prevent work hardening. Do not exceed the rated maximum drilling depth of 3.1875 inches in a single pass without retracting to clear chips.