A typical E glass composition is {HEAD ~ about 53.5%} by {TAIL ~ weight silicon dioxide} , about 8% boron oxide , about 14.5% aluminum oxide , about 21.7% calcium oxide , and about 1.1% magnesium oxide  
A typical E glass composition is { HEAD ~ about 53.5 % } by { TAIL ~ weight silicon dioxide } , about 8 % boron oxide , about 14.5 % aluminum oxide , about 21.7 % calcium oxide , and about 1.1 % magnesium oxide
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH