Hertel 2387389 Screw Machine Drill Bit Size 21 Tin Hss

Product Description

The HERTEL 2387389 is a screw machine length drill bit designed for high-throughput drilling in metal, plastic, and composite materials. Built from high-speed steel (HSS) with a titanium nitride (TiN) coating, it delivers extended tool life and reduced friction in production drilling environments. The bit features a 135-degree split point for fast penetration and self-centering entry without a pilot hole. At 2.125 inches overall length, this stub-length geometry provides added rigidity, making it well-suited for CNC drilling, drill press work, and screw machine operations where chatter and deflection must be minimized.

This bit is a standard choice for machinists, tool-and-die professionals, and production shop technicians drilling wire gauge size 21 holes at 0.1590 inch diameter. The short overall length and straight-cylindrical shank seat securely in standard three-jaw chucks and collet systems. The web-thinned, parallel-web construction reduces thrust load at the cutting edge, which is especially useful in harder workpiece materials where feed force control matters.

Key Features

• Wire size 21 at 0.1590 inch diameter for precise gauge-matched drilling
• TiN coating increases surface hardness and reduces built-up edge on ferrous materials
• 135-degree split point self-centers on entry, eliminating the need for a center punch in most applications
• Screw machine (stub) length of 2.125 inches overall provides superior rigidity over jobber-length bits
• Web-thinned parallel web lowers axial thrust and extends cutting edge life
• Right-hand spiral flute design for standard clockwise rotation in conventional drilling setups
• Straight-cylindrical shank compatible with standard chucks and collet holders

Compatibility

Designed as an OEM-style replacement or direct-use screw machine length drill bit for wire gauge size 21 applications in production machining and general metalworking setups.

Installation Notes

Installation and use should be performed by qualified machinists or tool operators familiar with cutting tool safety practices. Secure the shank fully in the chuck or collet before operation and confirm runout is within acceptable limits before cutting. Do not exceed the recommended feed and speed ratings for the workpiece material and bit diameter. Ensure the spindle is fully stopped before tool changes, and follow applicable OSHA and shop safety protocols when handling and storing cutting tools.