Hertel 66692161 Cobalt Drill Bit Size 40 Wire 135 Deg

Product Description

The HERTEL 66692161 is a cobalt screw machine length drill bit designed for high-speed drilling in tough materials including stainless steel, hardened alloys, and cast iron. It cuts in wire gauge size 40, which equals 0.0980 inches in decimal. The 135-degree split point reduces walking and lowers thrust required to start a hole without a center punch. A titanium nitride (TiN) coating adds surface hardness and extends tool life in production and repetitive drilling operations. With an overall length of 1-13/16 inches and a flute length of 13/16 inch, this stub-length geometry provides increased rigidity and reduces deflection. Machinists, tool and die workers, and maintenance mechanics use this bit in drill presses, CNC machines, and hand-held power tools.

This bit is suited for screw machine shops, production floors, and maintenance environments where tight tolerances and consistent hole quality are required. The right-hand spiral flute design handles ferrous and non-ferrous metals effectively. The straight-cylindrical shank seats in standard three-jaw chucks and collet holders without modification. It is rated as a heavy-duty grade bit, making it appropriate for interrupted cuts and work-hardening materials where standard high-speed steel bits wear prematurely. Web-thinning with a parallel web configuration reduces cutting resistance at the tip.

Key Features

• Wire gauge size 40 (0.0980 inches decimal) with straight-cylindrical shank of matching diameter
• 135-degree split point with web-thinned, parallel web configuration for reduced thrust and no center-punch requirement
• Cobalt construction with TiN coating for extended tool life in stainless, alloy steel, and hard metals
• Screw machine (stub) length at 1-13/16 inches OAL for added rigidity and reduced deflection
• Right-hand cut with regular spiral flute for efficient chip evacuation
• Heavy-duty grade rated for production drilling and work-hardening materials

Compatibility

Designed as a direct-fit replacement for wire gauge size 40 screw machine drill bits used in standard three-jaw chucks, collet systems, and quick-change tooling holders that accept a 0.0980-inch straight-cylindrical shank.

Installation Notes

Installation is performed by machinists and tool operators following standard toolroom practice. Secure the shank fully in the chuck or collet and verify runout before use. Power down and lock out the machine before changing or inspecting bits. Cutting speed and feed rate should be set per the material being drilled — do not force the bit at excessive feed rates, as cobalt bits are harder but more brittle than standard high-speed steel and can fracture under shock loading.