A slate hammer pokes a small hole in the back of the slate and makes a beveled hole in the face. A sharp blow with the point of the slate hammer punches a small hole (the size of a hammer point) through the first couple of layers of the slate, and the percussion of the hit blows out the rest of the layers, leaving a conical hole. Ideally, the larger hole on the slate's face makes a countersink for the nail head. Back to Roofing With Slate