Channel 18#A 180*68*7.0 theory weight 20.174, section area 25.69, channel 18#B 180*70*9.0 theory weight 23, section area 29.29, average leg thickness 10.5, inner arc radius 10.5, leg end arc radius 5.25
You don't know where to use this data, in general, the characteristics of the data channel in section area and theoretical weight, I suggest you refer to GB/T 706-2008 "hot rolled steel", see annex, hoping to help you.
