Hertel 74131608 Screw Machine Drill Bit 27/64 in Cobalt

Product Description

The HERTEL 74131608 is a screw machine length drill bit designed for high-production drilling applications where rigidity and heat resistance are critical. Built from cobalt tool steel with a titanium aluminum nitride (TiAlN) coating, this bit handles hard and abrasive materials that standard HSS tooling cannot manage reliably. The 135-degree split point reduces walking and lowers thrust force at entry, making it well suited for drilling without a center punch. The overall length of 3.375 inches and flute length of 2 inches reflect the compact, stub-length geometry that minimizes deflection in CNC and turret setups. Machinists, tool and die techs, and maintenance pros use this bit when they need consistent hole quality in alloy steels, stainless, and cast iron.

This drill bit fits standard screw machine, turret lathe, and drill press operations requiring a 27/64 inch diameter hole (0.4200 inch decimal equivalent). The straight-cylindrical shank fits into standard drill chucks and collet holders without modification. Right-hand spiral flutes evacuate chips efficiently in through-hole and blind-hole applications. Its web-thinned, parallel-web geometry reduces the chisel edge load and helps the split point self-center on entry.

Key Features

• Cobalt tool steel construction provides elevated heat resistance for drilling hard and work-hardening materials
• TiAlN coating extends tool life by reducing friction and resisting oxidation at high cutting temperatures
• 135-degree split point self-centers on entry and reduces required thrust force
• Web-thinned parallel web lowers chisel edge resistance for cleaner hole starts
• Screw machine (stub) length geometry minimizes deflection in tight setups and short-travel spindles
• Right-hand spiral flutes with regular helix provide reliable chip evacuation in a wide range of materials

Compatibility

Designed as a direct-fit screw machine length drill bit for any drill press, CNC turret, or lathe tailstock chuck accepting a straight-cylindrical shank in the 27/64 inch diameter range.

Installation Notes

Installation should be performed by a qualified machinist or maintenance technician familiar with rotating cutting tools. Always power down and lock out the spindle before changing tooling. Secure the straight-cylindrical shank fully in a properly sized collet or drill chuck to the depth recommended by the chuck manufacturer to prevent pullout under load. Do not exceed the speed and feed ranges recommended for cobalt tooling in the workpiece material being drilled.