Reduced Shank Drill Bits

A reduced shank drill bit has a shank diameter smaller than its cutting diameter so it fits standard chucks; use them when you need large-diameter holes but your drill or chuck cannot accept the full-size shank

Select high-speed steel (HSS) for general use, cobalt or M35/M42 blends for harder metals, and look for coatings like TiN or TiAlN to increase wear resistance and heat performance on metal drilling tasks

Check your drill chuck maximum capacity and choose reduced shank bits whose shank fits that capacity; common options include round reduced shanks, Morse taper adapters, and threaded or hexagonal adapters for quick-change use

Keep bits clean and dry, sharpen or replace worn tips, use appropriate cutting speeds and lubrication for the material, and store in a rack or case to prevent damage and corrosion

Use lower speeds and steady feed pressure for larger diameters, apply cutting fluid for metals, peck-drill to clear chips in deep holes, and avoid excessive side load to prevent bit breakage

Reduced shank bits are often more economical for occasional large-diameter work because they let you use standard chucks rather than requiring specialized equipment; prices vary widely depending on material and brand, with budget options under $50 and professional sets costing more

Wear eye protection, secure the workpiece, use the correct speed and cutting fluid, ensure the bit is properly seated in the chuck or adapter, and avoid loose clothing or gloves that could catch in the rotating tool