Precision Twist Drill 5996033 Cobalt Aircraft Drill Bit No 29

Product Description

The PRECISION TWIST DRILL 5996033 is a cobalt aircraft extension drill bit designed for drilling in tough materials including hardened steel, stainless steel, and high-temperature alloys. It carries a No. 29 wire gauge designation, corresponding to a decimal diameter of 0.136 inches, and features a 135-degree split point that self-centers on contact and reduces walking without a center punch. The straw finish indicates a heat-treatment process that increases surface hardness. At 6 inches overall length with a 1.75-inch flute, this bit reaches into recessed or extended-reach drilling applications where a standard-length drill cannot fit. Aerospace technicians, machinists, and maintenance professionals are the primary users.

This drill bit is suited for aerospace, aviation, and general metalworking applications where an extended reach is required. The 6-inch overall length makes it practical for drilling through structural assemblies, deep bosses, or stacked material layers. It belongs to the Series CO501-6 line, which is built to NAS 907 Type J standards. The right-hand spiral flute geometry with a 2-flute, 4xD flute-length-to-diameter ratio evacuates chips efficiently in through-hole and deep-hole drilling scenarios. General-purpose tool performance rating makes it appropriate for production and maintenance environments alike.

Key Features

• Cobalt tool material provides heat resistance for drilling hardened and abrasive metals
• 135-degree split point is self-centering and reduces the need for a center punch
• 6-inch overall length with 1.75-inch flute delivers extended reach into confined or deep locations
• Straw finish coating increases surface hardness and extends bit life
• Web-thinned, tapered web configuration reduces thrust and improves chip clearance
• Built to NAS 907 Type J standards for aerospace-grade dimensional compliance

Compatibility

Designed as an OEM-style replacement or direct-use drill bit for applications requiring a No. 29 wire size, 0.136-inch diameter, straight-cylindrical shank drill in extended-length cobalt construction.

Installation Notes

Installation is performed by machinists, aerospace technicians, or maintenance professionals using a standard drill press, hand drill, or CNC spindle with a compatible chuck accepting a 0.136-inch straight cylindrical shank. Ensure the workpiece is securely fixtured before beginning any drilling operation. Use appropriate cutting fluid for cobalt bits when drilling ferrous or hardened materials to extend bit life and reduce heat buildup. Inspect the split point for damage before each use and replace if the cutting edges are chipped or the web thinning is compromised.