... 2mm-150mm, Threaded, Straight and round shank, It could be used for glass, tile and stone drilling, The normal total length is 70mm ... Drill Bits, also know as Diamond Hole Saws, are used to drill glass,ceramics, porcelain, ceramic and porcelain tile, limestone, slate, ... —150mm ,it is very easy to use , just add water for lubrication.Pictures: Zinc plated diamond hole saw for glass ,marble or ceramic