47 ABNT NBR 7007-2016 2016-09-14 Portuguese Carbon steel and high-strenght low-alloy steel for strutural use - Requirements 48 ABNT NBR 6643-2016 2016-09-14 Portuguese Iron alloys - Determination of silicon, phosphorus, manganese, carbon and sulfur iron-manganese-silicon alloys 49 ABNT NBR IS...