In the cross section, {HEAD ~ the lower flange} is thicker than {TAIL ~ the upper flange} and the lower flange is wider than the upper flange, and the neutral axis of upward/downward bending 
is thicker than
In the cross section , { HEAD ~ the lower flange } is thicker than { TAIL ~ the upper flange } and the lower flange is wider than the upper flange , and the neutral axis of upward / downward bending
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL 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