Hertel 66693987 Letter Y Jobber Drill Bit Hss Tin

Product Description

The HERTEL 66693987 is a Letter Y jobber-length drill bit designed for production holemaking in metal and similar materials. Built from heavy-duty high speed steel with a titanium nitride (TiN) coating, it delivers extended tool life and reduced friction compared to uncoated HSS tooling. The 135-degree split point starts on contact without center-punching and minimizes walking on flat surfaces. With an overall length of 5.25 inches and a flute length of 3.875 inches, it fits standard drill chucks and CNC machines that accept a 0.4040-inch straight cylindrical shank. This bit is installed and used by machinists, toolroom technicians, and maintenance mechanics.

This drill bit is suited for general-purpose and heavy-duty holemaking applications in ferrous and non-ferrous metals, plastics, and composite materials. The jobber-length format is the most common configuration for bench drills, turret lathes, drill presses, and handheld power tools. The Letter Y size corresponds to a decimal diameter of 0.4040 inches, which falls within the 0.4000 to 0.5000 inch drill size range. The web-thinned, tapered web design reduces thrust requirements and improves chip evacuation in deeper holes.

Key Features

• Letter Y drill size - 0.4040 inch decimal diameter
• 135-degree split point for self-centering starts and reduced thrust
• TiN coating for increased surface hardness and extended tool life
• Heavy-duty high speed steel construction rated for NAS specification
• Two-flute regular spiral with web-thinned tapered web for efficient chip removal
• Straight cylindrical shank - 0.4040 inch diameter - fits standard chucks

Compatibility

Designed as a jobber-length drill bit for use in standard drill chucks, drill presses, CNC machining centers, and handheld power tools that accept a 0.4040-inch straight cylindrical shank.

Installation Notes

Installation is performed by machinists or maintenance technicians using a standard keyed or keyless chuck. Ensure the machine spindle is fully stopped and locked out before changing tooling. Secure the shank fully within the chuck jaws to the recommended engagement depth to prevent slippage under load. Use appropriate cutting fluid or coolant for the workpiece material to maximize tool life, noting this bit does not support coolant-through operation.