Precision Twist Drill 6001405 Letter M Hss Extension Drill

Product Description

The PRECISION TWIST DRILL 6001405 is a Letter M aircraft extension drill bit designed for deep-hole drilling applications where standard-length bits cannot reach. Built from high speed steel with an oxide finish, it measures 12 inches in overall length with a 3.0625-inch flute length, giving technicians the reach needed for structural and airframe work. The 135-degree split point is self-centering and web-thinned, which reduces walking on entry and lowers thrust load. The straight-cylindrical shank at 0.295 inches diameter fits standard drill chucks without an adapter. This drill ships individually and is suited for use by aviation maintenance technicians, HVAC installers, and metalworking tradespeople who need extended reach in steel, aluminum, and similar materials.

The 6001405 fits production and MRO applications where a Letter M hole size is required at depth. The 12-inch overall length makes it practical for drilling through structural members, deep cavities, bulkheads, or framing where a jobber-length bit would not reach. The spiral flute geometry promotes chip evacuation during extended cuts. Right-hand cutting direction is standard for conventional drill press and hand-drill use. This bit is a general-purpose tool appropriate for sheet metal, mild steel, and aluminum in both shop and field settings.

Key Features

• 135-degree split point reduces walking and lowers entry thrust
• Self-centering geometry eliminates the need for a center punch on most materials
• Web-thinned, tapered web configuration reduces cutting resistance
• 12-inch overall length provides extended reach for deep or obstructed drilling locations
• High speed steel construction with oxide finish for general-purpose metal drilling
• Meets NAS 907 Type B standard

Compatibility

Designed as a general-purpose Letter M aircraft extension drill bit compatible with standard straight-shank drill chucks accepting a 0.295-inch shank diameter.

Installation Notes

Extension drill bits of this length should be secured firmly in a keyed or keyless chuck and run at speeds appropriate for the workpiece material and bit diameter. Always clamp or secure the workpiece before drilling to prevent rotation. Wear appropriate eye protection and ensure cutting fluid is used when drilling ferrous materials to extend bit life. Inspect the split point for wear or damage before each use, as a dull or chipped point will cause walking even on self-centering geometry.