Such materials include {HEAD ~ metals} such as an aluminum alloy or {TAIL ~ stainless steel}, a polymer such as Acetal and composites 
such as
Such materials include { HEAD ~ metals } such as an aluminum alloy or { TAIL ~ stainless steel } , a polymer such as Acetal and composites
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH