Ideal for professional like woodworkers, electricians, and construction workers, as well as craft enthusiasts seeking efficient and accurate drilling in demanding tasks Engineered with helical grooves for enhanced chip ejection, this countersink drill bit set promotes faster drilling speeds and reduced heat buildup, making it a versatile option for extended projects across multiple industries This 11 piece metal Coated Countersink Drill Bit Set boasts wear resistance with a 50% durability increase, featuring a 1 / 4 inch hexagonal shank for secure tool compatibility and adjustable depth experimental holes for woodworking applications Designed with advanced metal coating and a standard hexagonal shank, the set includes bits # 4 to # 12 for adjustable depth countersinking, ensuring smooth surfaces without post processing and largest drilling diameters up to 3.4mm in various materials Perfect for scenarios such as furniture assembly, home renovation, and model crafting, these bits efficiently handle wood, aluminum, and with their quick chip removal design to blockages, Manufacturer: Greabuy