Hertel C.E05.0635 Aircraft Extension Drill Bit 1/4 in

Product Description

The HERTEL C.E05.0635 is an aircraft extension drill bit sized at Letter E (0.2500 inches decimal equivalent) with a 12-inch overall length, designed for drilling in tight or deep-reach applications where a standard-length bit cannot access the work area. The 135-degree split point is self-centering and reduces the need for a center punch, improving positional accuracy on entry. Constructed from high-speed steel with an oxide finish, the bit runs a 2-flute right-hand spiral flute with a tapered, web-thinned configuration that supports chip evacuation and reduces thrust during drilling. Licensed HVAC, aviation maintenance, and mechanical contractors use this bit for structural and sheet-metal work requiring extended reach.

This drill bit is suited for general-purpose metal drilling in applications where standard drill bit lengths are insufficient. The 12-inch extended shank gives access to recessed panels, deep cavities, and tight framing bays common in aircraft structures, HVAC ductwork framing, and mechanical equipment installations. The straight cylindrical shank with a 0.2500-inch diameter seats in standard 3-jaw drill chucks. The right-hand cutting direction and 2.75-inch flute length make it effective in both handheld and drill-press setups on ferrous and non-ferrous materials.

Key Features

• 135-degree split point is self-centering and reduces walk on entry without a center punch
• 12-inch overall length provides extended reach into deep cavities and recessed panels
• High-speed steel construction with oxide finish resists heat and wear during metal drilling
• Tapered, web-thinned configuration reduces cutting thrust and improves chip clearing
• Right-hand, 2-flute spiral design supports efficient swarf evacuation
• Straight cylindrical shank fits standard 3-jaw drill chucks without adapters

Compatibility

Designed as a general-purpose aircraft extension drill bit compatible with standard 3-jaw drill chucks accepting a 0.2500-inch straight cylindrical shank, suitable for handheld drills and bench drill presses used in metal fabrication and maintenance applications.

Installation Notes

Secure the straight shank firmly in a properly sized chuck before operation and verify the chuck key is removed before starting the drill. Use appropriate cutting fluid when drilling ferrous metals to extend bit life and reduce heat buildup. Wear ANSI-rated eye protection at all times during use. Inspect the cutting edges and flute geometry before each use and replace the bit if chipping or excessive wear is present.