Mexco DCX90 Dry Diamond 11 Piece Dry Core Drill Set. The DCX90 range of dry core drills are ideal for the plumber, builder and general tradesman providing a versatile kit for drilling holes in masonry from 38mm – 127mm. Mexco dry core drills should be used in conjunction with a minimum 850W+ drill motor fitted with a slipping clutch. Orders placed over a weekend or Bank Holiday will leave on Monday. Ireland, Scottish Isles, Channel Isles, all other isles off the mainland.