Precision Twist Drill 5998141 Cobalt Jobber Drill 11/32 in

Product Description

The PRECISION TWIST DRILL 5998141 is a cobalt jobber-length drill bit designed for heavy-duty drilling in ferrous and non-ferrous metals. Built from cobalt high-speed steel with a straw oxide finish, it handles elevated heat better than standard HSS bits, making it a reliable choice for production and maintenance drilling in steel and similar alloys. The 135-degree split-point geometry reduces walking on contact and requires less thrust to initiate a cut. At 4.75 inches overall length with a 3.4375-inch flute, it delivers the reach and chip-clearing capacity needed for most through-hole applications in structural and sheet stock.

This drill bit is sized at 11/32 inch (0.3438 inch decimal) and is suited for general-purpose drilling in steel, stainless, cast iron, aluminum, and plastics. The straight cylindrical shank fits standard 3-jaw chucks on drill presses, hand drills, and CNC drilling spindles. A two-flute regular spiral configuration promotes efficient chip evacuation in both hand-held and machine setups. Machinists, millwrights, pipefitters, and maintenance technicians working in light manufacturing, fabrication shops, or field service will find it a capable everyday bit for hole sizing, clearance holes, and production runs.

Key Features

• Cobalt high-speed steel construction for improved heat and wear resistance in steel drilling
• 135-degree split-point tip reduces bit walking and lowers required feed pressure
• Straw oxide finish provides mild lubricity and corrosion resistance during storage and use
• Web-thinned tapered web for reduced chisel-edge width and easier penetration
• Regular two-flute spiral for reliable chip evacuation in through-hole and blind-hole applications
• Meets ANSI and NAS 907 standards for heavy-duty jobber drill geometry

Compatibility

Designed for use in standard straight-shank drill chucks across handheld drills, drill presses, and CNC drilling machines. Belongs to the R10CO-R15CO-R18CO series. Compatible with primary workpiece materials coded P, M, K, N, and S, covering steel, stainless steel, cast iron, non-ferrous metals, and superalloys per ISO material classification.

Installation Notes

Secure the straight shank fully in a properly sized drill chuck before operation. Coolant-through capability is not supported on this bit, so apply cutting fluid externally when drilling hard or thick steel to manage heat buildup. Reduce feed rate and use adequate clamping when drilling thin stock to avoid breakthrough grab. Inspect the cutting edges before use and replace if chipping or excessive wear is present.