Dewalt bi metal deep cut holesaws 16 127mm dewalt dt8179 qz this 79mm deep cut holesaw from dewalt has been manufactured with m3 steel cutting edges which strengthen each tooth for longer life and a flexible strong body the longer life contributes towards better performance while offering a 125 mm deeper cut than a standard bi metal holesaw other features include a quick release mandrel to prevent lock up of the holesaw enabling easy removal dewalt dt8179 qz bi metal deep cut holesaw