Item Type: Keyhole Router Bits Set Material: Main Body Carbon Steel + Bit Alloy Shank Diameter: 1/4in Diameter of Cutter Head: 1/2in, 3/8in, 5/16in Blade Depth: 7/16in1Carbon Steel Main Body: The main body of the keyhole drill set is made of high quality carbon steel, with backlash resistance design, the edge is safer, sharper and more durable. 2Wide 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. 3Alloy Blade: The high quality 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. 4Application: The milling cutter set is suitable for wood, MDF, laminate, particleboard, plywood compact panels, acrylic, etc. , to avoid cutting metal and non wood materials. 51/4in Shank: 1/4in 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. 3 x Milling Cutter 3 x Storage Box