Hertel 66691320 Screw Machine Drill Bit 15/64 Cobalt

Product Description

The HERTEL 66691320 is a screw machine length drill bit designed for high-production drilling in metal fabrication, machining, and maintenance applications. Built from cobalt steel with a titanium nitride (TiN) coating, this bit delivers extended tool life in hard and abrasive materials. The 135-degree split point reduces walking on contact and requires less feed pressure at the start of the cut. At 2-7/16 inches overall length, the screw machine length profile provides added rigidity compared to jobber-length bits, making it well suited for drill press and CNC turret work where short, stiff tooling reduces deflection and improves hole accuracy.

This drill bit is used in metalworking shops, HVAC fabrication, plumbing rough-in, and electrical panel work where drilling through steel, stainless, cast iron, or other ferrous materials is routine. The 15/64 inch diameter is a common size for clearance holes, tapping pre-drill operations, and sheet metal work. The straight cylindrical shank fits standard three-jaw drill chucks on bench drill presses, hand drills, and CNC turret heads. The heavy-duty cobalt grade makes it appropriate for interrupted cuts and harder alloys where standard high-speed steel bits wear prematurely.

Key Features

• Cobalt steel construction with TiN coating for extended wear resistance in ferrous and hard materials
• 135-degree split point reduces thrust force and eliminates center-punch requirement on most metals
• Screw machine length (2-7/16 inches OAL) provides superior rigidity and reduced deflection versus jobber-length bits
• Web-thinned parallel web design improves chip evacuation and reduces heat buildup
• Right-hand spiral flute, regular spiral type for standard clockwise drilling operations
• Straight cylindrical shank fits standard drill chucks without adapters

Compatibility

Designed as a screw machine length drill bit for use in three-jaw drill chucks on bench drill presses, hand drills, and CNC turret machines accepting straight cylindrical shanks with a 0.2344 inch shank diameter.

Installation Notes

Installation and use of this drill bit should be performed by qualified machinists or trade professionals familiar with rotating cutting tools. Ensure the drill chuck is fully tightened and the workpiece is securely clamped before operation. Use appropriate cutting fluid or coolant when drilling hard alloys to preserve coating life and bit geometry. Inspect the cutting edges for wear or chipping before each use and replace the bit when point geometry is compromised.