Diablo's High-Speed Steel Forstner Bits feature a hardened steel body and an ultra-sharp spur for an accurate drill hole. The steep, angled cutting edges produce smooth, flat holes in all types of wood. Minimum chuck size of 1/4" Drills 3/8" holes in all types of wood without splintering High-speed steel body with an ultra-sharp spur for an accurate hole without walking on material Quality forged construction for extended bit life Steep, angled cutting edges to produce holes that are smooth and flat