Hertel 74131806 Letter G Cobalt Screw Machine Drill Bit

Product Description

The HERTEL 74131806 is a screw machine length drill bit sized to Letter G (0.2610 inches decimal equivalent) and designed for high-production drilling applications where rigidity and heat resistance matter. Built from cobalt high-speed steel with a TiAlN (titanium aluminum nitride) coating, it handles hard ferrous metals, stainless steel, and abrasive alloys that standard HSS tooling cannot manage. The 135-degree split point reduces thrust force and self-centers on contact, eliminating the need for a center punch in most setups. With an overall length of 2.625 inches and a flute length of 1.4375 inches, the shortened screw machine geometry increases stiffness and reduces deflection compared to jobber-length bits.

This bit is suited for metalworking operations in manufacturing, maintenance, and tool-room environments. The straight-cylindrical shank seats directly into drill chucks, CNC machining centers, and gang drill fixtures without adapters. The right-hand spiral flute evacuates chips upward during drilling. Web-thinned parallel web construction reduces chisel edge width, improving penetration in tough materials. Machinists, tool-and-die technicians, and maintenance mechanics are the primary users of screw machine length drill bits in this size range.

Key Features

• Letter G size: 0.2610 inches decimal equivalent, within the 0.2500 to 0.3000 inch range
• Cobalt HSS construction resists heat buildup in hard and abrasive metals
• TiAlN coating extends tool life and improves lubricity at elevated cutting temperatures
• 135-degree split point self-centers and reduces entry thrust force
• Web-thinned parallel web lowers chisel edge resistance for cleaner entry
• Screw machine (stub) length increases rigidity and reduces deflection versus jobber-length bits

Compatibility

Designed as a direct-fit replacement or standard tooling selection for any drill chuck or collet accepting a straight-cylindrical shank in the 0.2610 inch diameter range, including drill presses, CNC machining centers, and hand-held power drills used in metalworking applications.

Installation Notes

Installation is performed by machinists and tooling technicians. Secure the shank fully into the chuck and tighten according to the machine manufacturer's torque or clamping procedure. Ensure the workpiece is firmly clamped before drilling to prevent bit walk or breakage. Use appropriate cutting fluid or coolant for the material being drilled; note that this bit does not support coolant-through delivery. Inspect the cutting edges and coating condition before each use and replace tooling showing visible chipping or wear.