Hertel 42181 Cobalt Drill Bit 9/64 in 135 Degree Split Point

Product Description

The HERTEL 42181 is a screw machine length cobalt drill bit designed for drilling into tough, hard-to-machine materials. Built from M35 cobalt high-speed steel with an oxide straw coating, this bit delivers heat resistance and edge retention that standard HSS bits cannot match. The 135-degree split point geometry reduces walking on entry and requires less feed force, making it well suited for production drilling and repetitive hole-making. At 1-15/16 inches overall length with a 15/16-inch flute, the stub-length body provides added rigidity and minimizes deflection in short-reach drilling applications.

This bit is intended for use in screw machines, drill presses, and handheld power drills where hole quality and tool life in hard materials are priorities. Primary workpiece materials include hardened steels, heat-treatable alloyed steels, stainless steel, and titanium alloys. The 9/64-inch diameter and 3xD flute-to-diameter ratio make it a practical choice for machinists, maintenance technicians, and metalworking professionals handling production runs or repair drilling on ferrous and exotic metal components.

Key Features

• M35 cobalt steel construction for elevated heat resistance and extended tool life in hard materials
• 135-degree split point reduces thrust force and prevents bit walking on entry
• Oxide straw coating provides lubricity and additional surface hardness
• Stub screw machine length increases rigidity and reduces deflection
• Regular spiral flute promotes efficient chip evacuation
• No coolant-through requirement simplifies setup in standard drill press and screw machine applications

Compatibility

Designed as a screw machine length stub drill for use in standard drill chucks and screw machine spindles accepting 9/64-inch shank tooling. Suitable for drilling hardened materials, heat-treatable alloyed steels, stainless steel, and titanium alloy workpieces.

Installation Notes

Installation and use should be performed by qualified machinists or metalworking technicians familiar with proper speeds and feeds for cobalt tooling in hard materials. Secure the bit fully in the chuck before operation and verify chuck key removal prior to starting the machine. Use appropriate cutting fluid or mist coolant on stainless and titanium workpieces to extend bit life, even though coolant-through is not required by the bit design. Inspect the cutting edges for wear regularly, especially when drilling abrasive or hardened alloys.