Hertel C.E07.0345 Aircraft Extension Drill Bit No.29 Cobalt

Product Description

The HERTEL C.E07.0345 is a cobalt aircraft extension drill bit engineered for drilling in tight spaces and deep setups where standard-length bits cannot reach. Built to NAS 907 standards, this bit features a 135-degree split point that self-centers on contact, reducing walking and the need for a center punch. The straw finish cobalt construction handles harder alloys, stainless steel, and high-temperature materials with greater heat resistance than standard HSS. At 12 inches overall length with a 1.75-inch spiral flute, it delivers reach without sacrificing chip evacuation. Licensed HVAC, plumbing, and mechanical contractors use extension bits like this when drilling through structural members, deep wall cavities, or equipment frames.

This bit is designed for aircraft-style drilling applications where extended reach is required. The No. 29 wire gauge size (0.1360 inch decimal) suits common pilot hole and tap-clearance work across sheet metal, mild steel, stainless, and other ferrous materials. The straight cylindrical shank fits standard drill chucks. Right-hand cutting direction, two-flute spiral geometry, and a tapered web-thinned configuration promote efficient chip removal during deep or extended-reach drilling operations in both shop and field conditions.

Key Features

• 135-degree split point with self-centering tip reduces walking and eliminates center-punch step
• Cobalt tool material with straw finish for enhanced heat and wear resistance in hard materials
• 12-inch overall length provides extended reach for deep cavities and confined installations
• Web-thinned tapered web configuration reduces thrust and improves cutting efficiency
• NAS 907 standard construction for consistent dimensional accuracy
• Right-hand spiral flute geometry promotes positive chip evacuation on through-holes

Compatibility

Designed as a general-purpose aircraft extension drill bit compatible with any standard drill chuck accepting a 0.1360-inch straight cylindrical shank. Suitable for use with corded or cordless drills and drill presses across metalworking, mechanical, and trade installation applications.

Installation Notes

Installation should be performed by qualified tradespeople familiar with metalworking drill practices. Secure the workpiece before drilling and verify chuck grip on the straight shank before applying feed pressure. Use cutting fluid or lubricant when drilling stainless or hard alloys to extend bit life and manage heat buildup. Inspect the cutting edges before each use and replace the bit if chipping or excessive wear is observed.