Hertel C.E07.0391 Aircraft Extension Drill Bit No.23 Cobalt

Product Description

The HERTEL C.E07.0391 is a cobalt aircraft extension drill bit engineered for demanding drilling applications in hard or abrasive materials. Built to wire gauge size No. 23, it delivers a decimal diameter of 0.154 inches with a 135-degree split point that self-centers on contact, reducing walking and the need for a center punch. The straw finish indicates heat-treated cobalt steel construction. At 12 inches overall length with a 2-inch spiral flute, this bit is sized for reaching fastener locations in aircraft structures, deep housings, and confined assemblies. It meets NAS 907 standards and is suited for installation or maintenance technicians who drill into stainless steel, titanium, or high-strength alloys.

This bit is used in aerospace maintenance, heavy equipment repair, and industrial fabrication where standard-length bits cannot reach. The 12-inch extended reach makes it practical for drilling through structural panels, thick flanges, or layered assemblies. Right-hand cutting direction and a straight cylindrical shank allow use in standard drill chucks. The two-flute spiral geometry clears chips efficiently during through-drilling operations. General-purpose tool performance classification makes it a reliable option for job-shop and field-service environments handling a range of base materials.

Key Features

• No. 23 wire size, 0.154-inch decimal diameter for precision hole sizing
• 135-degree split point with self-centering geometry reduces setup time
• Cobalt steel construction with straw finish for heat and wear resistance
• 12-inch overall length provides extended reach into deep or confined workspaces
• Web-thinned, tapered web configuration reduces thrust and improves chip evacuation
• Meets NAS 907 standard for aircraft-grade tooling

Compatibility

Designed as an OEM-style aircraft extension drill bit for use in standard straight-shank drill chucks; suitable for applications requiring NAS 907-compliant tooling in aerospace, industrial, and heavy-equipment service environments.

Installation Notes

This bit is typically installed and operated by machinists, aerospace maintenance technicians, or industrial tradespeople using a standard drill press, hand drill, or right-angle drill with a compatible chuck. Secure the straight cylindrical shank firmly in the chuck before operation and verify chuck runout is within acceptable limits to avoid deflection at extended length. Use appropriate cutting fluid when drilling stainless steel, titanium, or other hard alloys to prolong bit life and prevent work hardening. Inspect the split point for chipping or wear before each use and replace if the self-centering geometry is compromised.