Hertel 66692070 Drill Bit Size 31 Cobalt Tin 135 Deg

Product Description

The HERTEL 66692070 is a screw machine length drill bit designed for high-speed, precision drilling in metal and hard materials. Built from heavy-duty cobalt steel with a titanium nitride (TiN) coating, this bit delivers extended tool life and reduced heat buildup in demanding production environments. It features a 135-degree split point for fast penetration and self-centering entry without a center punch. The straight-cylindrical shank measures 0.1200 inches in diameter, matching the wire gauge size 31 cutting diameter. Overall length is 1.875 inches with a flute length of 0.875 inches, making it compact and rigid for short-hole applications. Installed by machinists, tool and die technicians, and maintenance professionals.

This drill bit is suited for screw machine work, CNC drilling operations, and bench drill press applications where a short, stiff bit is required to minimize deflection. The 0.1200-inch decimal diameter falls within the 0.1000 to 0.1500-inch size range, appropriate for tapping prep holes, clearance holes, and pilot drilling in ferrous metals, stainless steel, and other tough alloys. The TiN coating reduces friction and extends cutting edge life compared to uncoated cobalt bits. Its web-thinned, parallel web configuration improves chip evacuation and reduces thrust force during entry.

Key Features

• Heavy-duty cobalt construction for heat resistance in hard-material drilling
• TiN coating reduces friction and extends cutting edge service life
• 135-degree split point enables self-centering entry and fast penetration
• Web-thinned parallel web reduces thrust and improves chip clearance
• Screw machine (stub) length provides rigidity and minimizes deflection
• Right-hand spiral flute with regular helix for consistent chip removal

Compatibility

Designed as an OEM-style replacement or standard tooling selection for screw machines, CNC lathes, drill presses, and machining centers accepting a 0.1200-inch straight-cylindrical shank drill bit.

Installation Notes

Install and remove drill bits only with the spindle fully stopped and the machine powered down. Secure the straight-cylindrical shank firmly in the chuck or collet to the full recommended grip depth to prevent slippage under load. Use appropriate cutting fluid or coolant for the workpiece material when drilling ferrous metals to manage heat, noting this bit does not have through-coolant capability. Follow applicable OSHA machine guarding and personal protective equipment requirements when operating drilling equipment.