Chicago-latrobe 55439 Reduced Shank Drill Bit 39/64 in

Product Description

The CHICAGO-LATROBE 55439 is a reduced shank twist drill bit designed for portable drilling applications across a range of materials. The bit measures 39/64 inch (0.6094 inch decimal) in cutting diameter with a 1/2 inch straight-cylindrical shank, allowing it to chuck into standard 1/2 inch drill chucks despite the larger cutting diameter. Constructed from high speed steel with a coated finish, it features a 118-degree standard point angle and a 2-flute right-hand spiral configuration. Overall length is 6 inches with a 3-1/8 inch flute length. Diameter tolerance is held to +0.0000 to -0.0012 inch, consistent with general-purpose jobber-style performance. Licensed tradespeople and skilled maintenance technicians will find this bit suited for day-to-day drilling tasks in the field or shop.

This drill bit is rated for general-purpose portable drilling. Primary workpiece material is wood, with secondary suitability for alloy steel, carbon steel, cast iron, and wood in mixed-material applications. The reduced shank design — shank diameter 1/2 inch versus cutting diameter 39/64 inch — allows use in standard 1/2 inch keyed or keyless chucks on corded and cordless drills. Series 190 identifies this as part of CHICAGO-LATROBE's general-purpose coated HSS line, appropriate for production maintenance, HVAC rough-in, plumbing, and general construction drilling tasks where a larger hole diameter is needed without requiring a larger chuck capacity.

Key Features

• Reduced shank (1/2 inch) allows a 39/64 inch cutting diameter to fit standard 1/2 inch drill chucks
• High speed steel construction handles steel, cast iron, wood, and general-purpose materials
• 118-degree standard point angle for versatile entry on flat and curved workpieces
• Coated finish for improved wear resistance and chip evacuation
• Right-hand cut, 2-flute regular spiral design for consistent chip clearing
• Diameter tolerance of +0.0000 to -0.0012 inch for consistent hole sizing

Compatibility

Designed for use in any 1/2 inch capacity keyed or keyless drill chuck. Suitable for portable drills used in HVAC, plumbing, electrical, and general construction trades where a 39/64 inch hole diameter is required.

Installation Notes

Secure the shank fully into the chuck before drilling and verify chuck tightness to prevent slippage under load. Power down and disconnect the drill or lock the trigger before changing bits. No coolant is specified for this bit; dry drilling is the standard method. Dispose of worn bits per shop or jobsite scrap metal procedures.