The particular material used, 7075 aluminum, is a readily available alloy of aluminum, {HEAD ~ zinc}, magnesium, copper and {TAIL ~ chromium} 
The particular material used , 7075 aluminum , is a readily available alloy of aluminum , { HEAD ~ zinc } , magnesium , copper and { TAIL ~ chromium }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL