For pricechoose optionsSelect Option 10mm 12mm 20mm 28mm 43mm 68mm 6mm 8mm Quantity Add to Basket RUBI Dry Cut Diamond Drill Bits for dry drilling in ceramic, porcelain, natural stone and other materials. Usable with grinder. Supplied in blister.Specifications:Max. Operating Speed: 14,000 r.p.m.Thread: M14.