Hertel 66691668 Screw Machine Drill Bit Letter Q Cobalt

Product Description

The HERTEL 66691668 is a screw machine length drill bit designed for high-speed metal drilling in production and job-shop environments. Manufactured from heavy-duty cobalt steel with a titanium nitride (TiN) coating, it holds cutting edge hardness under elevated heat generated in tough ferrous and non-ferrous materials. The split point geometry at 135 degrees reduces walking on entry and lowers thrust requirements compared to conventional 118-degree points. At 3 inches overall length with a 1-11/16-inch flute, the screw machine format keeps the tool rigid and reduces deflection in short-reach drilling applications. A licensed machinist or toolroom technician is the typical installer.

This drill bit is sized at Letter Q, equal to 0.3320 inches decimal, and fits within the 0.300 to 0.350 inch drill size range. It is suited for production drilling on CNC machining centers, drill presses, and turret lathes where a straight-cylindrical shank is required. The regular spiral flute evacuates chips effectively in both through-hole and blind-hole operations. Web-thinned, parallel web construction reduces cutting resistance at the chisel edge, making it practical for stainless steel, alloy steel, cast iron, and other hard materials where standard HSS bits underperform.

Key Features

• Cobalt steel construction with TiN coating for extended tool life in hard and abrasive materials
• 135-degree split point reduces entry walking and lowers required feed force
• Web-thinned parallel web decreases chisel edge resistance for cleaner starts
• Screw machine length at 3 inches OAL provides rigidity and minimizes deflection
• Right-hand spiral flute with regular helix for consistent chip evacuation
• Straight-cylindrical shank at 0.3320 inches diameter for standard chuck compatibility

Compatibility

Designed as an OEM-style replacement or direct-use screw machine drill bit for drill presses, CNC machining centers, and turret lathes accepting a straight-cylindrical shank in the 0.300 to 0.350 inch size range.

Installation Notes

Installation and use should be performed by a qualified machinist or toolroom technician familiar with drill press or CNC setup procedures. Secure the shank fully in the chuck or collet before operation and verify runout before engaging the workpiece. Always power down and lock out the machine before changing tooling per applicable OSHA lockout/tagout requirements. Do not exceed the recommended feed and speed parameters for the workpiece material and machine spindle.