Hertel 66693516 Screw Machine Drill Bit Letter N Hss Tin

Product Description

The HERTEL 66693516 is a screw machine length drill bit sized to Letter N (0.3020 inches) with a 135-degree split point and a titanium nitride (TiN) coating over a high-speed steel body. Screw machine length bits run shorter than jobber bits, which reduces deflection and improves positional accuracy in production drilling, turret lathes, and screw machine applications. The split point geometry allows the bit to start on contact without a center punch, and the web-thinned parallel web reduces thrust force at the cut. Overall length is 2-13/16 inches with a 1-5/8 inch flute length. This is a heavy-duty grade tool suited for demanding production environments.

This bit is designed for right-hand cutting in metal fabrication, machining, and maintenance applications where a compact drill length is required for rigidity or clearance. The straight-cylindrical shank at 0.3020 inches diameter seats directly in standard drill chucks and quick-change holders without adapters. Typical applications include drilling mild steel, stainless, aluminum, and similar materials where a TiN coating is specified to reduce wear and extend tool life. No coolant-through capability; external coolant or cutting fluid is recommended for extended runs in harder materials.

Key Features

• Letter N size (0.3020 inches decimal equivalent) for precise hole sizing
• 135-degree split point starts without center punching and reduces walking
• TiN coating over high-speed steel for improved wear resistance and tool life
• Screw machine length (2-13/16 inches OAL) provides increased rigidity over jobber-length bits
• Web-thinned parallel web lowers thrust requirements during drilling
• Straight-cylindrical shank fits standard chucks and quick-change tooling

Compatibility

Designed as a direct-fit replacement or production drill for any application requiring a Letter N, 0.3020-inch straight-shank screw machine length bit in equipment accepting a 0.3020-inch cylindrical shank.

Installation Notes

Installation and use should be performed by machinists or qualified trade personnel familiar with drill press, lathe, or CNC tooling setup. Ensure the machine spindle is fully stopped and locked out before mounting or removing the bit from the chuck. Confirm shank seating and chuck tightness before starting the cut. Apply cutting fluid or external coolant when drilling steel or stainless to prevent premature coating breakdown.