Precision Twist Drill 5995775 Cobalt Extension Drill 15/64

Product Description

The PRECISION TWIST DRILL 5995775 is a cobalt aircraft extension drill bit designed for demanding drilling applications where reach and heat resistance are required. At 15/64 inch (0.2344 inch) in diameter and 12 inches in overall length, this bit extends access into deep or recessed workpieces that standard-length drills cannot reach. The 135-degree split point is self-centering, eliminating the need for a center punch on most metals and reducing walking on hard surfaces. A straw finish indicates cobalt construction throughout, suited for high-temperature cutting environments. Licensed HVAC sheet metal fabricators, aviation maintenance technicians, and industrial tradespeople are the primary users.

This bit is built for general-purpose metal drilling in applications that demand extended reach — including HVAC ductwork, aircraft structural panels, and heavy-gauge sheet metal. The 2-5/8 inch (2.625 inch) flute length handles chip evacuation efficiently during deep passes. The straight-cylindrical shank fits standard drill chucks without adapters, making it a straightforward drop-in for most corded and pneumatic drill setups used in field and shop environments. It conforms to NAS 907 Type J standards, which is a common requirement in aerospace and precision fabrication work.

Key Features

• 135-degree split point is self-centering for accurate starts without a center punch
• Cobalt construction provides heat and wear resistance when cutting hard metals
• 12-inch overall length gives extended reach into deep or obstructed drilling locations
• Straight-cylindrical shank fits standard drill chucks directly
• Right-hand spiral flutes with tapered web configuration for efficient chip evacuation
• Meets NAS 907 Type J standards for aerospace and precision fabrication applications

Compatibility

Designed as a general-purpose cobalt extension drill bit compatible with standard drill chucks accepting a 15/64 inch (0.2344 inch) straight-cylindrical shank, suitable for use in metal fabrication, HVAC sheet metal work, and aerospace maintenance applications conforming to NAS 907 Type J.

Installation Notes

This bit is installed by machinists, sheet metal workers, and aircraft maintenance technicians using standard corded or pneumatic drills. Secure the straight shank fully in the chuck and verify concentricity before drilling to prevent bit deflection over the extended 12-inch length. Use appropriate cutting fluid when drilling hard or stainless alloys to prolong tool life. Disconnect power to any drill press or pneumatic supply before changing bits.