Hertel 76606722 Cobalt Stub Drill Bit No. 27 135 Point

Product Description

The HERTEL 76606722 is a cobalt stub-length drill bit designed for drilling into high-tensile strength metals. It carries a No. 27 wire gauge size, which corresponds to a decimal diameter of 0.144 inches, and features a 135-degree split point with web thinning for fast, self-centering starts without a center punch. The 1/4-28 threaded shank interfaces with compatible quick-change holders used in aerospace and precision sheet-metal work. At 0.5625 inches overall length, this stub-length geometry provides maximum rigidity and minimizes deflection in tight-clearance drilling applications. Cobalt construction with an oxide coating improves heat and wear resistance compared to standard HSS bits.

This bit is suited for production drilling in stainless steel, titanium alloys, Inconel, and other hard or work-hardening metals where standard HSS tooling fails prematurely. The stub OAL and tapered web configuration reduce chatter on thin-gauge sheet and structural members. It meets NAS 965 Type D specification, making it appropriate for aerospace maintenance, military depot work, and precision fabrication shops where material traceability and dimensional compliance are required. Machinists and aircraft maintenance technicians are the primary users.

Key Features

• No. 27 wire gauge size - 0.144 inch decimal diameter
• 135-degree split point with web thinning for self-centering entry
• Cobalt construction with oxide coating for heat and wear resistance
• Stub-length OAL of 0.5625 inches for maximum rigidity and reduced deflection
• 1/4-28 threaded shank for use with compatible quick-change drill holders
• Meets NAS 965 Type D specification

Compatibility

Designed for use with 1/4-28 threaded quick-change shank systems. Rated for general-purpose drilling in high-tensile strength metals per NAS 965 Type D specification.

Installation Notes

Install into a compatible 1/4-28 threaded shank holder and confirm secure engagement before use. Use appropriate cutting fluid or coolant when drilling hard alloys to extend tool life and maintain hole tolerance. Right-hand cutting direction - confirm drill press or hand drill is set to forward rotation. Follow applicable shop safety and PPE requirements when operating rotary cutting tools.