A circular hollow section (CHS) is being used as a tension member in a truss. We do not know the exact details of the connection, but it is likely that a slotted plate connection, such as the one shown below, would be used. You should assume that for this type of connection that you lose 7.5% of the cross sectional area to cut the slot in the CHS, and that the tension correction factor kt=0.88.
A1. Choose the Grade C250 of least mass from Austube Mills hollow section properties that will satisfy this design load. Load of the design tension N* for the CHS is 298kN. Use AS4100.