A non-contact, air-activated lifting and tamping device which incorporates a means of producing a Bernouilli airflow at the device nozzle, creating an adjacent low air pressure region for inducing lift; and which includes provision for high velocity air jets for tamping operation. A high-precision apparatus evaluates the creep damage of high tension heat resistant steel used in high temperature exposed apparatuses. The achievement of the finished thickness is controlled by at least one thickness measuring unit at the outlet of the roll stand, and deviations upward or downward therefrom are fed back in the form of an actuating signal for actuating the roll stand in order to appropriately increase or decrease the thickness reduction.