Hertel 66693144 No 28 Jobber Drill Bit 135 Deg Hss Tialn

Product Description

The HERTEL 66693144 is a wire gauge No. 28 jobber-length drill bit designed for precision holemaking in metal and hard materials. It is manufactured from heavy-duty high speed steel and finished with a TiAlN coating that extends tool life under high-heat cutting conditions. The 135-degree split point reduces walking on entry without a center punch and minimizes thrust load compared to conventional 118-degree points. The web-thinned, tapered web construction further reduces cutting resistance. At 2.875 inches overall length with a 1.75-inch flute length, this bit fits standard drill chucks and benchtop or handheld drilling equipment used by machinists, pipefitters, and maintenance technicians.

This drill bit is suited for production and maintenance drilling applications in ferrous and non-ferrous metals, plastics, and composite materials. The straight cylindrical shank, sized at 0.1405 inches in diameter, seats directly in keyless or keyed drill chucks without an adapter. The regular spiral, right-hand cutting geometry makes it compatible with standard clockwise-rotating drill presses, hand drills, and CNC drilling spindles. It is sold individually and carries an NAS specification designation, making it appropriate for aerospace-adjacent and industrial shop environments that require traceability to national standards.

Key Features

• No. 28 wire gauge size - 0.1405 inches decimal equivalent
• 135-degree split point with web thinning for self-centering entry and reduced thrust
• TiAlN coating increases surface hardness and heat resistance for extended tool life
• Heavy-duty high speed steel construction rated for hard-material drilling
• Regular spiral, 2-flute geometry with tapered web for efficient chip evacuation
• NAS specification designation for industrial and aerospace-adjacent traceability

Compatibility

Designed as an OEM-style jobber drill bit compatible with any standard drill chuck accepting a 0.1405-inch straight cylindrical shank, including keyless and keyed chucks on drill presses, hand drills, and CNC drilling spindles.

Installation Notes

Installation is performed by machinists, maintenance technicians, and pipefitters using standard drill presses or hand-held drilling equipment. Secure the shank fully in the chuck jaws and verify concentricity before cutting. Disengage and de-energize the drill before bit changes. Use appropriate cutting fluid or cooling for ferrous metals to preserve coating integrity and extend bit life.