Hertel 74130444 Cobalt Screw Machine Drill Bit 33/64 in

Product Description

The HERTEL 74130444 is a cobalt screw machine length drill bit designed for high-performance drilling in tough materials including stainless steel and difficult alloys. Built to the HSCO135 series standard, it features a 135-degree split point that reduces walking on entry and requires no center punch on most surfaces. The straight cylindrical shank measures 33/64 inches (0.5156 inches decimal) in diameter with an overall length of 3.875 inches, making it well-suited for close-tolerance work in short-clearance drilling setups. A web-thinned parallel web reduces thrust requirements and helps maintain chip flow in deep-hole applications. The two-flute regular spiral design is optimized for aggressive chip evacuation in ferrous and exotic metals.

This bit is used in machine shop, maintenance, and fabrication environments where standard high-speed steel tooling lacks the durability to handle work-hardening alloys such as 304 and 316 stainless steel, Inconel, and other tough alloys. It fits standard drill chucks and CNC machine spindles that accept straight-shank tooling. The screw machine length profile is common in production environments where a shorter tool profile improves rigidity and reduces deflection on the spindle. Licensed machinists, tool-and-die techs, and experienced fabricators are the primary users.

Key Features

• Cobalt construction provides superior heat resistance and wear life compared to standard HSS bits in stainless steel and tough alloy applications
• 135-degree split point reduces entry walking and lowers required thrust force
• Web-thinned parallel web improves chip clearing and reduces heat buildup in deep cuts
• Screw machine length (3.875 inches OAL) delivers increased rigidity and reduced deflection versus jobber-length bits
• Right-hand cutting, two-flute regular spiral design compatible with standard drill chucks and CNC spindles
• Straw finish (bright uncoated base with light oxidation) consistent with HSCO135 series tooling

Compatibility

Designed for use in standard straight-shank drill chucks and machine spindles accepting a 33/64-inch diameter shank. Primary workpiece materials are stainless steel and tough alloys per HSCO135 series specifications. Coolant-through drilling is not supported by this tool.

Installation Notes

Installation and use should be performed by qualified machinists or tooling technicians familiar with proper chuck torque and spindle speeds for cobalt tooling in ferrous materials. Ensure the drill press, lathe, or CNC spindle is fully powered down and locked out before changing tooling. Confirm chuck jaws are clean and free of debris before seating the shank to prevent runout. Do not use this bit in hammer-drill mode or rotary-percussion applications.