9 Piece Core Drill Kit – Slotted. Mexco core drill sets are available in both 7 & 11 piece versions, the DCX90 range of dry core drills kits are ideal for the plumber, builder and general tradesman providing a compact and versatile core drill kit for drilling holes in general masonry products. Drilling Soft Facing Brick, Drilling Concrete Blocks, Drilling Hard Sandstone, Drilling Coarse Sandstone, Drilling Soft Slate, Drilling Breeze Block & Drilling Lignacite Blocks. The Mexco 7 piece core drill kit contains. 38mm Dry Core Drill. 52mm Dry Core Drill. 117mm Dry Core Drill. 10mm x 175mm A-Taper Pilot Drill. Mexco dry core drills should be used in conjunction with a Minimum 850W + drill motor fitted with a slipping clutch.