Hertel 74130832 Cobalt Screw Machine Drill Bit Size 31

Product Description

The HERTEL 74130832 is a cobalt screw machine length drill bit designed for high-speed drilling in tough materials including hardened steels, stainless steel, and heat-resistant alloys. Built to wire gauge size 31 with a decimal diameter of 0.1200 inches, this bit features a 135-degree split point that reduces walking on entry and lowers the thrust required to start the cut. The overall length is 1-7/8 inches, and the flute length measures 7/8 inch, making this a compact stub-length tool suited for close-quarters drilling in production and machine shop environments. Two regular spiral flutes evacuate chips efficiently during operation.

This bit is commonly used in machining, fabrication, and maintenance applications where precise small-diameter holes are required in ferrous metals. The screw machine length profile provides added rigidity compared to jobber-length bits, reducing deflection during short-hole drilling. It is well suited for drill press, CNC, and turret lathe applications. Licensed machinists, tool and die makers, and industrial maintenance technicians typically spec this type of bit for production runs involving hardened or work-hardening materials.

Key Features

• Cobalt construction provides heat resistance for drilling hardened and stainless steels
• 135-degree split point reduces thrust and prevents bit walking on entry
• Web-thinned parallel web design improves chip flow and reduces cutting torque
• Screw machine (stub) length adds rigidity and minimizes deflection in short-hole applications
• Straight cylindrical shank fits standard drill chucks without adapters
• Right-hand cutting, regular spiral flute pattern for conventional drilling operations

Compatibility

Designed as an OEM-style replacement or direct-application screw machine drill bit for use in standard drill chucks accepting a straight cylindrical shank in small-diameter wire gauge sizes.

Installation Notes

Installation of this bit requires insertion into a compatible drill chuck and tightening with the appropriate chuck key before operation. Always ensure the spindle is fully stopped before changing tooling. Use appropriate cutting fluid or coolant when drilling hardened or stainless materials to extend tool life, noting that this bit does not support coolant-through delivery. Follow applicable shop safety standards and machine guarding requirements during use.