Diamond core drill Diameter: 2"-14", width: 3.5mm or 4. ... "-18", adaptor: 1/4" UNC Wet cutting Diamond core drill 1.Wet cut drilling reinforced commcrete,block,glass,ceramics.2.Make hole ... hard aggregates, green concrete, asphalt and abrasive materials.Machinery:Core drill machine and hand drill, driven by hydraulic power station ... 1/4"UNC If you are interested in this products, please ask more question.