Chemical Symbol Zr.) – Element No. 40 of the periodic system. Atomic weight 91.22. Specific gravity 6.5 and melting point at about 3200° +1300° F. Because of its great affinity for oxygen and combines readily with nitrogen and sulphur it is used as a deoxidizer and scavenger in steel making. It is used as an alloy with nickel for cutting tools and is used in copper alloys. Many of the definitions as shown in this section of the catalog have been printed through the courtesy and permission of “Metals Handbook” – American Society of Metals. “Metals and Alloys Dictionary” – Chemical Publishing Co., Inc.