Cleveland C13188 Aircraft Drill Bit Letter E 1/4 in 135 Pt

Product Description

The CLEVELAND C13188 is an aircraft extension drill bit designed for deep-hole drilling applications requiring extended reach. Built from high-speed steel with a bright, uncoated finish, this bit features a 135-degree split point with web thinning for self-centering entry and reduced feed pressure. The 12-inch overall length and 2.75-inch spiral flute accommodate drilling through stacked materials, structural members, or confined-space locations where a standard-length bit falls short. With a straight cylindrical shank and right-hand cutting direction, it mounts directly into standard drill chucks. Licensed HVAC, mechanical, and electrical trades alongside aerospace and structural technicians rely on this type of bit for precision work in tight or extended-reach conditions.

This bit is suited for general-purpose drilling in metal, composite, and similar materials where extended reach is required. The 1/4-inch diameter (Letter E sizing, 0.2500 inches decimal) and tapered web configuration make it appropriate for through-holes in structural panels, equipment enclosures, sheet metal assemblies, and similar trade applications. It is intended for use in hand drills, drill presses, and right-angle drive tools accepting a straight cylindrical shank.

Key Features

• 135-degree split point with web thinning for self-centering and reduced walking on entry
• 12-inch overall length provides extended reach for deep or obstructed drilling locations
• High-speed steel construction handles general-purpose drilling in metal and composite materials
• Bright, uncoated finish compatible with a wide range of cutting fluids and lubricants
• Right-hand spiral flute evacuates chips efficiently during through-hole operations
• Meets NAS 907 Type B standards for consistent dimensional accuracy

Compatibility

Designed as a general-purpose aircraft extension drill bit conforming to NAS 907 Type B, suitable for use in standard straight-cylindrical-shank drill chucks across a range of portable and stationary drilling equipment.

Installation Notes

Installation and use of this drill bit should be performed by qualified technicians following applicable workplace safety and trade codes. Secure the workpiece firmly before drilling and verify the chuck is tightened to the shank before operation. Apply appropriate cutting fluid or lubricant to extend tool life and improve hole finish when drilling metal. Inspect the bit for wear or damage before each use and replace if the cutting edges are dull or the shank is deformed.