A tool by means of which the vertically true position of a pivot hole in a clock plate or part, in relation to a corresponding hole in the opposite plate or part, may be correctly marked or drilled. It has an accurately machined table or platform with a pump centre on which the work is centred and clamped. A column secured to the edge of the table carries an arm through which a centre runner or drilling attachment is inserted in precise alignment with the axis of the pump centre. When required itis sometimes possible to centre the work from the centre runner above, and drill through the table in place of the pump centre. Uprighting can also be carried out using the mandril lathe.