Hertel 74131129 Cobalt Screw Machine Drill Bit Size 60

Product Description

The HERTEL 74131129 is a cobalt screw machine length drill bit designed for high-speed drilling in tough materials including stainless steel, high-temp alloys, and hardened steels. Built to wire gauge size 60 (0.0400 inches decimal), it features a 135-degree split point that reduces walking and requires no center punch on most surfaces. The stub-length body - 1.375 inches overall - provides rigidity in short-reach applications where standard-length bits would deflect. A web-thinned, parallel-web configuration improves chip evacuation and reduces thrust load. Two regular spiral flutes and a straight cylindrical shank make this bit compatible with standard drill chucks and quick-change holders. The straw finish indicates heat treatment and is left uncoated for direct use out of the box.

This bit is suited for precision drilling in metalworking, fabrication, and maintenance applications where a compact, rigid tool is required. The screw machine length profile is commonly used in CNC drilling, turret lathes, and bench-top drill press setups where clearance is limited. It is appropriate for drilling non-ferrous metals, carbon steel, and work-hardened materials where standard high-speed steel bits wear prematurely. Machinists, tool and die makers, and industrial maintenance technicians are the primary users of this style and size.

Key Features

• Wire gauge size 60 with 0.0400 inch decimal diameter for precision small-hole work
• 135-degree split point reduces thrust and eliminates center-punch requirement on most surfaces
• Cobalt construction provides heat resistance for drilling stainless and high-temp alloys
• Screw machine (stub) length of 1.375 inches overall for maximum rigidity and reduced deflection
• Web-thinned parallel web improves chip flow and lowers cutting force
• Right-hand cutting with regular spiral flutes and straight cylindrical shank for universal chuck compatibility

Compatibility

Designed as a screw machine length drill bit for use in standard drill chucks, CNC tool holders, and quick-change systems accepting a straight cylindrical shank in the 0.0000 to 0.1000 inch diameter range.

Installation Notes

Install the shank fully into the chuck and tighten securely before starting any drilling operation. Verify spindle speed is appropriate for the workpiece material and bit diameter before engaging the cut. Cobalt bits should not be used on wood or masonry, as this wastes the alloy's heat-resistance properties and does not improve cut quality. Secure the workpiece firmly to prevent movement, particularly when drilling small-diameter holes at high RPM.