Hertel 74131897 Screw Machine Drill Bit Letter P Cobalt

Product Description

The HERTEL 74131897 is a screw machine length drill bit sized to Letter P (0.3230 inches) and built from cobalt steel with a TiAlN coating. Screw machine length bits run shorter than jobber length, which increases rigidity and reduces deflection in high-production drilling applications. The 135-degree split point starts on contact without a center punch and cuts aggressively through hard and abrasive materials. With a 2-15/16-inch overall length and a 1-11/16-inch flute length, this bit is designed for use in drill presses, CNC machines, turret lathes, and screw machines where a stubby, stiff tool is required.

This bit is suited for metalworking environments where heat and tool wear are primary concerns. The cobalt construction handles stainless steel, high-alloy steels, cast iron, and other hard ferrous materials that would quickly degrade standard high-speed steel tooling. The TiAlN coating adds a thermal barrier that allows higher cutting speeds and extends tool life in dry or minimally lubricated operations. Machinists, tool and die makers, and production drillers working in job shops or manufacturing facilities are the primary users of this type of tooling.

Key Features

• Letter P size at 0.3230 inches decimal equivalent for precise bore sizing
• Cobalt steel construction resists heat and wear in hard-material drilling
• TiAlN coating extends tool life and supports higher surface footage
• 135-degree split point reduces thrust and eliminates the need for center punching
• Web-thinned parallel web geometry improves chip evacuation and reduces cutting load
• Screw machine length body increases rigidity and minimizes deflection in production setups
• Right-hand spiral flute with straight-cylindrical shank for standard chuck compatibility

Compatibility

Designed as a production replacement or new-setup tooling for screw machines, turret lathes, drill presses, and CNC drilling operations requiring a straight-cylindrical shank drill bit in the Letter P size range.

Installation Notes

Install in a standard drill chuck or collet that accepts a straight-cylindrical shank, ensuring the shank is fully seated and the chuck is tightened with the key before operation. Power down the machine completely before changing tooling. Verify spindle speed is appropriate for the workpiece material and bit diameter before engaging the cut. Coolant-through is not supported on this bit, so ensure adequate chip clearing and heat management through feed rate and dwelling cycles when drilling deep holes.