Chicago-Latrobe 44420 5/16 in 118° Left-Hand Jobber Drill Bit

5/16 in Left-Hand Jobber Drill

The Chicago-Latrobe 44420 is a fractional-inch jobber-length drill bit measuring 5/16 inch with a 118-degree conventional point. It is manufactured from high-speed steel with a bright uncoated finish and features a left-hand helix for reverse cutting applications. The decimal equivalent is .3125 inch.

Machinists needing reverse extraction

This bit suits machinists and maintenance technicians who need to remove broken fasteners or create threads for left-hand screws. The left-hand helix pulls chips away from the operator during reverse operation. Buyers requiring coolant-through capability or a coated surface for extended wear in abrasive materials should look elsewhere.

5/16 inch capacity in steel and alloys

The .3125-inch diameter handles general-purpose drilling in steel, cast iron and non-ferrous alloys at standard jobber lengths. The 118-degree point centres quickly without a pilot hole in most materials. The uncoated high-speed steel substrate limits tool life in high-temperature alloys or prolonged production runs where heat buildup accelerates wear.