Hertel 83238766 Screw Machine Drill Bit Letter H Hss

Product Description

The HERTEL 83238766 is a screw machine length drill bit designed for high-volume production drilling in metal fabrication, machining, and general industrial applications. Built from high-speed steel with an oxide coating, this bit carries a Letter H designation, equating to 0.2660 inches (17/64 inch) in diameter. The 135-degree split point reduces walking on contact and requires less feed pressure than a standard 118-degree point. The web-thinned construction further eases penetration into ferrous and non-ferrous metals. Licensed machinists, tool-and-die technicians, and maintenance mechanics are the primary installers of this bit type.

This screw machine length drill bit is suited for use in drill presses, CNC machining centers, manual mills, and hand-held drill motors where a shorter, more rigid bit is preferred over a jobber-length equivalent. The reduced overall length of 2-11/16 inches increases rigidity and helps control deflection in tight workholding setups. It is classified as a heavy-duty grade and conforms to NAS 907 specification under NAS designation, making it appropriate for aerospace-adjacent and precision manufacturing environments. Typical applications include through-hole and blind-hole drilling in steel, aluminum, cast iron, and similar structural metals.

Key Features

• Letter H size (0.2660 inches / 17/64 inch) with straight-cylindrical shank of matching diameter
• 135-degree split point reduces thrust force and self-centers on contact without a center punch
• High-speed steel construction with oxide coating for heat and wear resistance
• Screw machine length (2-11/16 inches OAL) provides added rigidity over jobber-length bits
• Web-thinned, parallel-web design reduces cutting resistance and chip packing
• Conforms to NAS 907 specification for precision and aerospace-adjacent applications

Compatibility

Designed as a direct-fit replacement for Letter H screw machine length drill bits conforming to NAS 907 specification, compatible with any standard straight-shank drill chuck accepting a 0.2660-inch shank diameter.

Installation Notes

This bit is installed by machinists and tool technicians in any drill chuck or collet rated for a 0.2660-inch straight-cylindrical shank. Ensure the chuck or collet is fully tightened and the workpiece is secured before starting the spindle. Use appropriate cutting fluid for the workpiece material to extend tool life and improve hole finish. Inspect the cutting edges and point condition before each use; a damaged split point will increase thrust load and reduce hole accuracy.