a rod formed of {HEAD ~ an alkaline metal alloy} tempered to have {TAIL ~ a tensile strength} of at least about 600 psi 
tempered to have
a rod formed of { HEAD ~ an alkaline metal alloy } tempered to have { TAIL ~ a tensile strength } of at least about 600 psi
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH