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