Eagle Cutting Tool C1090-051-I Cobalt Drill Bit 51/64

Product Description

The EAGLE CUTTING TOOL C1090-051-I is a 51/64-inch cobalt screw machine (stub-length) drill bit with a 1/2-inch straight shank. Cobalt high-speed steel construction provides elevated heat resistance and hardness retention, making it well suited for drilling through tough ferrous metals, stainless steel, cast iron, and other hard-to-machine materials. The stub-length body offers increased rigidity compared to jobber-length bits, reducing deflection and improving hole accuracy in production and repair drilling applications. This bit is a practical choice for machinists, pipefitters, and maintenance technicians who need reliable performance on hard substrates.

The C1090-051-I is designed for use in drill presses, milling machines, and heavy-duty hand drills equipped with a 1/2-inch chuck. Stub-length cobalt bits like this one are commonly used in metal fabrication shops, mechanical maintenance environments, and plumbing or HVAC rough-in work where oversized clearance or pilot holes are required in steel plate, pipe flanges, or structural steel members. The 51/64-inch diameter is a close equivalent to a Letter drill or metric step in many standard hole-size progressions.

Key Features

• Cobalt high-speed steel construction resists heat buildup during prolonged drilling in hard metals
• Stub/screw machine length provides extra rigidity and reduced bit deflection
• 51/64-inch cutting diameter suits oversized clearance and pilot hole applications
• 1/2-inch straight shank fits standard 1/2-inch drill press and hand drill chucks
• Single-unit minimum order quantity for low-volume or replacement purchases

Compatibility

Designed as an OEM-style replacement or direct-use screw machine drill bit compatible with any drill press, mill, or hand drill accepting a 1/2-inch straight shank.

Installation Notes

Installation is performed by machinists or qualified tradespeople using a drill press or hand drill with a 1/2-inch chuck. Secure the shank fully in the chuck and verify concentricity before drilling. Use appropriate cutting fluid or lubricant when drilling stainless steel or hardened alloys to extend tool life. Always wear eye protection and secure the workpiece before operation.

Technical Specifications

• Cutting Diameter: 51/64 inches
• Shank Diameter: 1/2 inch
• Drill Type: Screw Machine (Stub Length)
• Material: Cobalt High-Speed Steel
• Weight: 0.69 pounds

Standard Information

• Brand: EAGLE CUTTING TOOL
• Manufacturer Part Number: C1090-051-I