Hertel 73041477 Cobalt Drill Bit No. 27 135 Split Point

Product Description

The HERTEL 73041477 is a cobalt threaded shank drill bit designed for drilling into high-tensile strength materials including hardened steels, stainless steel, and other tough alloys. It carries a No. 27 wire gauge size, equivalent to 0.1440 inches in diameter, and features a 135-degree split point for fast, accurate starts without center-punching. The oxide coating adds surface hardness and helps resist heat buildup during aggressive drilling operations. The 1/4-28 threaded shank provides positive engagement with compatible toolholders, preventing slippage under torque. Overall length is 2.125 inches with a 1.125-inch flute length. Cutting direction is right-hand with a regular spiral flute and tapered web configuration.

This bit is intended for production and maintenance drilling in metalworking environments where standard high-speed steel tooling fails prematurely. The cobalt construction makes it well-suited for aerospace, defense, and industrial fabrication applications that reference NAS 965 specifications. Typical users include machinists, maintenance technicians, and sheet metal workers drilling high-strength ferrous and nickel-based alloys. The web-thinned point reduces thrust requirements and extends tool life in difficult materials.

Key Features

• Cobalt construction for use in high-tensile strength and heat-resistant materials
• 135-degree split point starts on contact and reduces walking without a center punch
• Oxide coating improves surface hardness and dissipates heat during cutting
• 1/4-28 threaded shank locks securely into compatible threaded toolholders
• Web-thinned, tapered web design lowers drilling thrust and improves chip evacuation
• Meets NAS 965 specification for aerospace and industrial applications

Compatibility

Designed for use with toolholders and drill fixtures accepting a 1/4-28 threaded shank. Suitable for general-purpose drilling in high-tensile strength ferrous and non-ferrous materials per NAS 965 specification requirements.

Installation Notes

Installation and use should be performed by qualified machinists or maintenance technicians familiar with metalworking drill press, CNC, or hand-drill operations. Ensure the machine spindle is fully stopped and locked out before changing or inspecting tooling. Thread the shank fully into the holder and confirm secure engagement before applying cutting load. Use appropriate cutting fluid for the base material to maximize tool life and hole quality.