Hertel 66691403 Screw Machine Drill Bit 23/64 in Cobalt

Product Description

The HERTEL 66691403 is a cobalt screw machine length drill bit designed for high-speed drilling in tough materials where standard HSS bits fall short. Built from heavy-duty cobalt steel with a titanium nitride (TiN) coating, this bit delivers extended tool life in ferrous metals, stainless steel, and hard alloys. The 135-degree split point reduces thrust and starts on contact without center-punching. The overall length of 3-1/16 inches and screw machine (stub) length configuration make it well suited for use in drill presses, CNC machines, and turret lathes where rigidity and minimal deflection are priorities.

This drill bit is used in metal fabrication shops, machine shops, and maintenance environments where production drilling in hard or abrasive materials is routine. The straight cylindrical shank accepts standard three-jaw chucks. Its screw machine length keeps the bit short and stiff, reducing chatter and improving hole straightness in high-cycle applications. Licensed machinists, tool and die makers, and industrial maintenance technicians are the primary installers and operators of this tooling.

Key Features

• Cobalt construction with TiN coating for extended life in hard and abrasive materials
• 135-degree split point starts on contact and reduces required thrust
• Web-thinned parallel web for improved chip evacuation
• Screw machine (stub) length provides added rigidity and reduced deflection
• Straight cylindrical shank fits standard three-jaw chucks
• Right-hand cutting, regular spiral flute for general-purpose metal drilling

Compatibility

Designed as an OEM-style replacement or direct-use cobalt stub drill bit for use in standard three-jaw drill chucks and machine tool holders accepting a 0.3594-inch straight cylindrical shank.

Installation Notes

This bit is intended for use by machinists and trained maintenance technicians operating drill presses, lathes, or CNC equipment. Always secure the shank fully in the chuck and verify zero runout before beginning a drilling cycle. Power down and de-energize the machine before installing or removing the bit. Use appropriate cutting fluid for the workpiece material to maximize tool life and hole quality.