Supported shapes of compound section Pattern Shape Parameters [mm] Double I section a Double Channel FtF (face to face position) a Double Channel BtB (back to back position) a Starred Angle (diagonal position) a Double Angle BtB (back to back position) a Double Angle FtF (face to face position) a Double Angle BtB LL (long leg - back to back position) a Double Angle FtF LL (long leg - face to face position) a Four Angle BtB (back to back position) a; b Four Angle FtF (face to face position) a; b Four Angle I a; b Double pipe a