Power Hammer test

I'm trying to think of a way to quantify how hard a hammer hits. I came up with this, it's easy to try, Metric folks could use the closest size and report results in MM's. Start with 8 inches of 1 inch sq bar, mild steel. Mark both ends at 2 inches. Use flat dies. Heat one end to near welding, put the mark on the edge of the die, hit 5 times real hard. Heat the other end, hit 10 times. Wire brush, cool, and measure how thick both ends came out.