1,Carbon Steel Main Body: The main body of the keyhole drill set is made of carbon steel, with backlash resistance design, the edge is safer, sharper and more durable. 2,Wide Uses: The suit can cut long T slots, and can also be used to make keyhole slots for pendants, photo frames, shelves, mirrors, cabinets, supporting devices and other wall hangings. 3,Alloy Blade: The heat treated alloy blade can be sharpened again, the bearing is sealed to achieve uniform rotation and precise cutting, and the 2 blade design helps to remove chips and make your work clean and smooth. 4,Application: The milling cutter set is suitable for wood, MDF, laminate, particleboard, plywood compact panels, acrylic, etc., to avoid cutting metal and non wood materials. 5,1 or 4in Shank: 1 or 4in shank drill bits provide greater stability and less vibration during use. Please clamp the shaft in the correct position and ensure that your router is the speed starts from 10000RMP to prevent the shaft from bending. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.