{HEAD ~ The total content} of these additional alloying elements should not exceed 1.0 percent by weight, {TAIL ~ preferably not over 0.5 percent} by weight 
not exceed
{ HEAD ~ The total content } of these additional alloying elements should not exceed 1.0 percent by weight , { TAIL ~ preferably not over 0.5 percent } by weight
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL REL OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH