Depends entirely on the materials used, the type of sword, type of steel, width, length, blade thickness, etc. For comparison, I have a shortsword, 1075 high carbon steel, 20 inch blade, 5 inch...
First, it is the medieval and it is flail. To answer your question, the average flail weighed 10 to 20 pounds depending on who was going to use it and if it was for cavalry or for hand to hand combat...
I looked this up and found out it was 45 pounds. I expected more and today's Army has it's people carry a heavier load. It depends on the type of armor you are referring to, as the medieval time...