Hertel 66693789 Jobber Drill Bit Letter D Hss Tin 4in

Product Description

The HERTEL 66693789 is a jobber-length drill bit sized to letter D (0.2460 inches) with a 135-degree split point and a titanium nitride (TiN) coating over a high speed steel (HSS) body. It is designed for holemaking in metal, wood, and general-purpose materials encountered in mechanical, electrical, plumbing, and HVAC trade work. The split point geometry reduces walking at drill startup without requiring a center punch. The TiN coating extends cutting edge life by reducing friction and heat buildup. Overall length is 4 inches with a 2-3/4 inch flute length. Installation or fabrication professionals who drill through sheet metal, pipe hangers, strut, or structural steel will find this bit suited to daily production use.

This drill bit fits standard 3-jaw chucks on handheld drills, drill presses, and magnetic base drills. The straight-cylindrical shank diameter matches the body at 0.2460 inches, making it compatible with any chuck that accepts fractional or letter-size shanks in that range. It is a heavy-duty grade bit rated to the NAS specification, appropriate for demanding trade applications including mechanical room fabrication, electrical rough-in drilling, and plumbing penetration work in light steel.

Key Features

• Letter D size - 0.2460 inches decimal equivalent
• 135-degree split point with web-thinned, tapered web for reduced thrust and no-walk startup
• TiN coating on high speed steel body for extended tool life in metal drilling
• Regular spiral, 2-flute design with 2-3/4 inch flute length for efficient chip evacuation
• Straight-cylindrical shank fits standard drill chucks without adapters
• Heavy-duty grade, NAS specification - suited for production and trade use

Compatibility

Designed as a jobber-length replacement drill bit for use in any standard drill chuck accepting a 0.2460-inch straight-cylindrical shank, including handheld drills, drill presses, and magnetic base drill units.

Installation Notes

Install this bit into a properly rated drill chuck and tighten with a chuck key before operation. Secure the workpiece with clamps or a vise before drilling - never hold freehand. Use appropriate cutting fluid when drilling ferrous metals to preserve coating life and reduce heat. Inspect the cutting edges before each use and replace the bit if chipping or dulling is observed to avoid workpiece damage or bit failure.