Dewalt tile drill bits 5 25mm dewalt dt6039 qz this 7mm drill bit from dewalt has been designed to perform the task of easy and accurate drilling of holes in glass slate granite and tiles including porcelain tiles up to grade 5 manufactured with safety in mind the central core created during drilling stops the drill from wandering while the core can be removed easily through the core ejection slot dewalt dt6039 qz tile drill bit 7mm