Hertel 66691270 Screw Machine Drill Bit 5/32 in Cobalt

Product Description

The HERTEL 66691270 is a screw machine length drill bit designed for short-hole drilling in metal fabrication, machining, and maintenance applications. Built from cobalt tool steel with a titanium nitride (TiN) coating, it handles hard and abrasive materials where standard high-speed steel bits wear prematurely. The 135-degree split point starts on contact without center-punching and reduces thrust. At 2-1/16 inches overall length with a 1-inch flute length, this stub-length geometry provides rigidity and reduces deflection in drill press and hand-drill applications. The straight-cylindrical shank measures 0.1562 inches in diameter and seats in standard three-jaw chucks.

This bit is suited for production and job-site drilling in steel, stainless steel, cast iron, and other tough alloys. Screw machine length bits are a standard choice when hole depth is shallow and maximum rigidity is required. Machinists, maintenance mechanics, pipefitters, and industrial trades reach for stub-length cobalt bits when drilling through hardened or work-hardened surfaces where longer bits would flex or chatter.

Key Features

• Cobalt tool steel construction handles hard and abrasive metals
• TiN coating reduces friction and extends cutting edge life
• 135-degree split point eliminates need for center punch and lowers drilling thrust
• Web-thinned, parallel-web design improves chip clearance
• Stub-length body at 2-1/16 inches overall reduces deflection and improves hole accuracy
• Right-hand spiral flute evacuates chips efficiently from the cutting zone

Compatibility

Designed as an OEM-style replacement or direct-use screw machine length drill bit for standard three-jaw drill chucks accepting a 0.1562-inch straight-cylindrical shank across bench drill presses, CNC drill stations, and portable drills.

Installation Notes

Secure the shank fully in the chuck before drilling and verify chuck key is removed before powering the machine. Use appropriate cutting fluid or coolant when drilling ferrous or stainless alloys to preserve coating life and edge geometry. Cobalt bits are more brittle than standard HSS; avoid side-loading or prying during use. Inspect the split point for chipping between uses, particularly after drilling hardened material.