General description High Efficiency Countersink Drill Bit Set designed for woodworking, featuring a depth stop and a center drill that quickly discharges chips from the hole, effectively preventing debris accumulation and improving drilling efficiency. Technical specifications Diameter: 28mm Material: High-speed steel (HSS) Features: Depth stop, center drill Usage Suitable for punching holes in wood, including solid wood, particle board, plywood, and MDF. Also effective for plastic, soft metal, and fiberboard. Other information Removable and adjustable: Length of the countersunk hole can be adjusted by removing the screw with the provided hex key, allowing for drilling of screws of different lengths.