Eagle Cutting Tool C1090-041-I Cobalt Drill Bit 41/64

Product Description

The EAGLE CUTTING TOOL C1090-041-I is a 41/64-inch cobalt screw machine (stub length) drill bit with a 1/2-inch straight shank. Cobalt construction provides superior heat resistance compared to standard high-speed steel, making this bit well suited for drilling hard and abrasive materials including stainless steel, cast iron, and high-alloy stock. The stub-length body offers increased rigidity and reduced deflection, which is especially valuable when drilling in tight clearance situations or on drill press work where chatter control matters. Licensed tradespeople and machinists reach for cobalt stub drills when production drilling demands consistent hole quality and extended tool life.

This drill bit is intended for use in machine shop, fabrication, and maintenance environments where drilling into hard ferrous and non-ferrous metals is routine. It fits standard 1/2-inch drill chucks on drill presses, magnetic base drills, and CNC-style machines. The 41/64-inch diameter is a common sizing step used in close-tolerance hole preparation, reaming pre-drill operations, and clearance hole work across mechanical, HVAC equipment, and structural fabrication applications.

Key Features

• Cobalt construction for improved heat resistance and longer tool life in hard-material drilling
• Stub screw machine length provides added rigidity and reduced bit deflection
• 41/64-inch cutting diameter suits close-tolerance and clearance hole applications
• 1/2-inch straight shank fits standard 1/2-inch drill chucks without adapters
• Minimum order quantity of 1 — available as a single unit

Compatibility

Designed as a replacement or production-use cobalt stub drill for standard 1/2-inch chuck drill presses, magnetic base drills, and compatible machine tool spindles requiring a 41/64-inch diameter cobalt screw machine drill.

Installation Notes

Secure the 1/2-inch shank firmly in a properly sized drill chuck before operation and verify chuck key is removed before powering the machine. Apply appropriate cutting fluid when drilling ferrous metals to extend bit life and maintain dimensional accuracy. Cobalt bits can be resharpened with a drill grinding fixture — inspect the cutting edges for wear before each use to avoid oversized holes or work hardening the base material. Always follow machine tool manufacturer guidelines and applicable shop safety standards when operating drilling equipment.

Technical Specifications

• Cutting Diameter: 41/64 inches
• Shank Diameter: 1/2 inch
• Drill Type: Screw Machine (Stub Length)
• Material: Cobalt
• Weight: 0.69 pounds

Standard Information

• Brand: EAGLE CUTTING TOOL
• Manufacturer Part Number: C1090-041-I