This European Standard specifies the tolerances for semi-finished products intended to undergo hot forming by forging, i.e. blooms and slabs, billets and rectangular billets: - made of general purpose steels, in accordance with EURONORM 30; - non-alloy and alloy steels for hardening and tempering, in accordance with EN 10083. It does not cover semi-finished products intended for drop forging which are covered by prEN 10243-1.