Hertel 83238790 Screw Machine Drill Bit Letter K Hss

Product Description

The HERTEL 83238790 is a screw machine length drill bit designed for high-production drilling in metal fabrication, machining, and maintenance applications. Built from high-speed steel with an oxide coating, this bit cuts in a right-hand direction and features a 135-degree split point for fast starts without center-punching on most surfaces. The web-thinned, parallel-web construction reduces thrust and improves chip evacuation. At 2.6875 inches overall length with a 1.5-inch flute length, the stub-length profile provides added rigidity compared to jobber-length bits, making it well suited for use in drill presses, CNC machines, and hand-held power tools in close-clearance work.

This bit is sized at Letter K, equivalent to 0.2810 inches (9/32 inch), and falls within the 0.2500 to 0.3000 inch decimal size range. It is appropriate for drilling ferrous and non-ferrous metals, plastics, and composite materials in both shop and field settings. The straight-cylindrical shank seats directly into standard three-jaw chucks and collet holders without adapters. Licensed machinists, millwrights, and maintenance technicians are the typical installers. It meets NAS 907 specification under NAS designation, which is common in aerospace and heavy industrial procurement.

Key Features

• 135-degree split point starts on contact without center-punching on most materials
• Web-thinned, parallel-web design reduces drilling thrust and improves chip flow
• Heavy-duty grade high-speed steel construction resists heat and wear in production use
• Oxide finish provides mild corrosion resistance and reduces friction during cutting
• Stub screw machine length adds rigidity over standard jobber-length bits
• Meets NAS 907 specification for industrial and aerospace procurement standards

Compatibility

Designed as an OEM-style replacement or standard-stock screw machine length drill bit for use in any application requiring a Letter K (0.2810 inch) straight-shank bit with a 135-degree split point.

Installation Notes

Installation is performed by machinists and maintenance technicians using standard drill presses, machining centers, or hand-held power drills with a compatible three-jaw chuck or collet. Ensure the machine is fully powered down and locked out before changing bits. Secure the shank fully into the chuck to the depth of the flute shoulder to prevent runout. Use appropriate cutting fluid for the material being drilled to extend tool life and maintain hole quality.