Hertel 66691619 Drill Bit Letter L Cobalt Tin 135 Deg

Product Description

The HERTEL 66691619 is a screw machine length drill bit sized at Letter L (0.290 inches decimal) with a 135-degree split point and a titanium nitride (TiN) coating over a cobalt steel body. Screw machine length bits are shorter than jobber-length bits, which increases rigidity and reduces deflection in production drilling, CNC operations, and close-tolerance work. The split-point geometry starts on contact without a center punch and reduces thrust requirements. The TiN coating adds surface hardness and helps extend tool life when drilling through mild steel, stainless, aluminum, and other ferrous and non-ferrous materials. This bit is rated heavy duty and suited for trade and industrial applications.

This drill bit is intended for use in drill presses, CNC machining centers, and hand-held power drills where a shorter, more rigid bit is preferred. The straight cylindrical shank at 0.290 inches fits standard 3-jaw chucks and collet-style toolholders commonly found in machine shop and production environments. The regular spiral flute with web-thinned, parallel web construction supports efficient chip evacuation in through-hole and blind-hole applications. Fabricators, maintenance machinists, and mechanical contractors will find this bit appropriate for general metalworking tasks requiring consistent hole quality.

Key Features

• Letter L size - 0.290 inches decimal diameter for precise sizing
• 135-degree split point starts on contact and reduces thrust force
• Cobalt steel construction with TiN coating for extended tool life in hard materials
• Screw machine (stub) length increases rigidity and reduces deflection
• Web-thinned parallel web supports chip evacuation in metal drilling
• Right-hand cutting direction, spiral flute, straight cylindrical shank

Compatibility

Designed as a direct-fit screw machine length drill bit for use in any standard 3-jaw drill chuck or collet toolholder accepting a 0.290-inch straight cylindrical shank.

Installation Notes

Installation is performed by qualified machinists or mechanical trade professionals. Secure the shank fully in the chuck or collet and verify runout before drilling. Always power down and lock out the machine before changing tooling. Follow applicable OSHA machine guarding and PPE requirements when operating drilling equipment.