1. A PROCESS FOR THE MANUFACTURE OF STEELS CONTAINING A FINE DISTRUBUTION OF NONMETALLIC INCLUSIONS AND HAVING GOOD CUTTING PROPERTIES OVER A WIDE RANGE OF CUTTING SPEEDS, WHICH COMPRISES PROVIDING THE STEEL WITH AN OXYGEN CONTENT OF 0.004 TO 0.1%, DEOXIDIZING THE STEEL IN THE MOLTEN STATE WITH A FERRO-ALLOY CONTAINING 45 TO 90% OF SILICON, 0.5 TO 40% OF CALCIUM, UP TO 4% OF ALUMINUM. 0.5 TO 8% OF MANGANESE AND REMAINDER IRON IN ADDITION TO IMPURITIES WHEREBY A PROTECTIVE LAYER OF OXIDIZED INCLUSIONS WILL BE FORMED ON A TOOL CUTTING THE STEEL