Irwin 63105ZR Cobalt Jobber Drill Bit 5/64 Inch

Product Description

The IRWIN 63105ZR is a cobalt jobber-length drill bit designed for general-purpose drilling in steel, cast iron, and other ferrous materials. Built to M35 material grade, it features a 135-degree split point that reduces walking and allows for faster penetration without a center punch. The bit has a 5/64-inch (0.0781 inch) diameter with a 2-inch overall length and a 1-inch flute length. The bright/uncoated finish suits applications where coating compatibility or re-sharpening is a consideration. Machinists, maintenance technicians, and trade professionals performing metal fabrication or field drilling tasks are the primary users.

This bit is suited for drilling steel and cast iron in both maintenance and light production environments. The straight cylindrical shank fits standard 3-jaw drill chucks on hand drills, drill presses, and magnetic drills. The 5/64-inch size is commonly used for pilot holes, tap drilling, and small fastener clearance holes in sheet metal and structural steel. The regular spiral flute geometry provides reliable chip evacuation in through-hole and shallow blind-hole applications. Maximum drilling depth is 1 inch.

Key Features

• M35 cobalt construction for improved heat resistance and extended tool life in ferrous metals
• 135-degree split point reduces thrust force and eliminates walking on flat or curved surfaces
• Right-hand cutting direction with regular spiral flute for standard drilling operations
• Bright/uncoated finish allows easy re-sharpening and is compatible with cutting fluid use
• Tapered web configuration adds core strength along the flute length
• Straight cylindrical shank fits standard chuck sizes without adapters

Compatibility

Designed as a general-purpose replacement or maintenance drill bit for use in standard 3-jaw chucks accepting a 5/64-inch straight shank, compatible with hand drills, drill presses, and similar drilling equipment used on steel and cast iron workpieces.

Installation Notes

This bit is installed by a machinist or maintenance technician into a compatible chuck and tightened securely before operation. Always ensure the workpiece is clamped or fixtured before drilling to prevent rotation or movement. Use appropriate cutting fluid or coolant when drilling steel to reduce heat buildup and extend bit life. Inspect the split point for wear or chipping before each use; a damaged point should be re-sharpened or the bit replaced.