Hertel 66693508 Drill Bit Letter M 135 Point Hss Tin

Product Description

The HERTEL 66693508 is a screw machine length drill bit sized at Letter M (0.2950 inches) and built for high-production drilling in metal and other hard materials. Constructed from heavy-duty high-speed steel (HSS) with a titanium nitride (TiN) coating, this bit delivers extended tool life and reduced friction compared to uncoated HSS. The 135-degree split point starts on contact without a center punch and reduces walking on flat or curved surfaces. With an overall length of 2.75 inches and a flute length of 1.5625 inches, the screw machine length profile fits close-quarters applications and automatic screw machine setups where a standard-length bit would not clear.

This drill bit is suited for use in CNC machining centers, turret lathes, automatic screw machines, and hand-held or bench drill press applications where tight clearances require a shorter tool. The straight-cylindrical shank at 0.2950 inches diameter seats directly in standard drill chucks and collet holders without adapters. The TiN coating makes it particularly effective on steel, cast iron, aluminum, and similar metals encountered in production shop and maintenance settings. A right-hand cut, regular spiral with web-thinned parallel web geometry promotes efficient chip evacuation and reduces thrust in deeper holes.

Key Features

• Letter M size: 0.2950 inches diameter for precise fractional sizing
• 135-degree split point starts on contact and reduces drill walking
• TiN coating extends tool life and lowers cutting friction
• Heavy-duty HSS construction handles interrupted cuts and hard materials
• Web-thinned parallel web reduces thrust load during drilling
• Screw machine length (2.75 inches OAL) fits tight-clearance setups

Compatibility

Designed as an OEM-style replacement or direct-fit drill bit for standard 3-jaw chucks and collet systems accepting a 0.2950-inch straight-cylindrical shank across drill presses, CNC turrets, and automatic screw machines.

Installation Notes

Installation is performed by machinists and tool-and-die or maintenance personnel. Secure the shank fully in the chuck or collet before operation and confirm runout is within acceptable tolerance for the application. Power down and lock out the machine spindle before changing tooling. Avoid exceeding the recommended surface footage for HSS in the material being drilled, as overheating will degrade the TiN coating and reduce tool life.