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