Precision Twist Drill 5999711 Cobalt Jobber Drill 11mm

Product Description

The PRECISION TWIST DRILL 5999711 is a cobalt high-speed steel jobber-length drill bit ground to an 11.00 mm (0.4331 inch) diameter with a 135-degree split point. The oxide and straw finish protects the cutting edges and aids in chip evacuation during sustained drilling operations. With an overall length of 142.00 mm (5-19/32 inches) and a flute length of 94.00 mm (3-45/64 inches), this bit is sized for general-purpose production drilling. The web-thinned, tapered web geometry reduces thrust and improves centering without a center punch on many setups. It meets DIN 338 and ANSI standards and is built to a heavy-duty grade. Machinists, tool-and-die workers, and maintenance mechanics are the primary users.

This bit is suited for drilling steel, stainless steel, cast iron, nonferrous metals, and high-temperature alloys, consistent with the P, M, K, N, and S workpiece material codes. It is a right-hand cutting, regular spiral-flute design appropriate for use in drill presses, CNC machining centers, and hand-held power drills where a straight-shank bit is required. The 9xD flute-to-diameter ratio provides adequate chip clearance in through-hole and moderate-depth drilling applications. No coolant-through capability is present, so external cutting fluid or flood coolant is recommended when drilling harder alloys.

Key Features

• Cobalt HSS construction for improved heat resistance and edge retention in ferrous and difficult-to-machine materials
• 135-degree split point with web thinning reduces walking and lowers thrust requirements at entry
• Oxide and straw coating resists heat buildup and protects flute surfaces during extended runs
• DIN 338 and ANSI specification compliance ensures dimensional interchangeability with standard toolholders and chucks
• Straight cylindrical shank (11.00 mm diameter) fits standard drill chucks without adapters
• Two-flute regular spiral design promotes consistent chip evacuation in through-hole and blind-hole drilling

Compatibility

Designed as a general-purpose replacement or production drill bit for applications requiring a straight-shank cobalt jobber drill in the 10.00 mm to 12.50 mm size range, conforming to DIN 338 and ANSI standards.

Installation Notes

Installation is performed by machinists or maintenance technicians using a standard keyed or keyless drill chuck rated for the shank diameter. Secure the shank fully into the chuck before operation and verify concentricity, especially in CNC or production setups. Apply a suitable cutting fluid or flood coolant when drilling steel or high-temperature alloys to extend tool life and prevent work hardening. Inspect the cutting edges for wear before each use; a dull cobalt bit generates excess heat and can damage the workpiece.