Chicago-latrobe 55480 Reduced Shank Drill Bit 1-1/4 in Hss

Product Description

The CHICAGO-LATROBE 55480 is a reduced shank twist drill bit designed for portable drilling applications in metal, wood, and cast iron. The bit carries a 1.25-inch cutting diameter with a 0.5-inch straight-cylindrical shank, allowing it to chuck into standard 1/2-inch capacity drill motors despite its oversized cutting head. Constructed from high speed steel with a coated finish, the 55480 is built for general-purpose production and field work where a full-size shank is not practical. A 118-degree standard point angle and two spiral flutes make it suitable for a broad range of workpiece materials without requiring special geometry or modified feeds.

This bit fits portable drilling setups on job sites and in fabrication shops. It is well suited for tradespeople who need to bore larger-diameter holes through structural steel, alloy steel, carbon steel, cast iron, or wood using a standard 1/2-inch chuck drill. The reduced shank design eliminates the need for a large-capacity drill press or heavy-duty chuck, making it a practical field solution for electricians, pipefitters, ironworkers, and general contractors running conduit or pipe penetrations through structural members.

Key Features

• 1.25-inch cutting diameter with 0.5-inch reduced shank fits standard 1/2-inch chucks
• High speed steel construction for durability across steel, cast iron, and wood applications
• 118-degree standard point angle for general-purpose drilling without special grinding
• Coated finish for improved wear resistance and reduced heat buildup
• Two spiral flutes with regular helix for consistent chip evacuation
• Right-hand cutting direction; compatible with standard portable drills

Compatibility

Designed for use in any 1/2-inch capacity portable drill chuck. Suitable for drilling wood, alloy steel, carbon steel, and cast iron as stated by the manufacturer for Series 190.

Installation Notes

Installation of this bit is performed by machinists, millwrights, and trade professionals using portable drills or drill presses equipped with a 1/2-inch chuck. Secure the shank fully into the chuck before applying power, and verify the chuck is tightened at all three key positions to prevent slippage under load. Wear appropriate eye protection and secure the workpiece before drilling. Reduce feed rate when breaking through the backside of the material to prevent bit walking or workpiece grab.