This is a core drill set for composite materials and drain mass from Miyanaga. It is a 3-piece set consisting of a Φ100 drill, an L-shank, and a center drill. The shank shape is straight. There are no chips on the blades. It has only been used about 2-3 times. The shank has some rust, but it can be used without any problems. The center drill blade is clean with no chips. Blade diameter: 100mm Effective length: 50mm (cutter length 77mm) Chuck size: L-shank straight 13mm Suitable materials: composite materials, metal siding boards, wood, FRP, PVC pipes, plastic drain mass Materials that can be drilled: metal (1mm thick), artificial marble, ceramic siding boards