I just did the square bar test on my 85lb. Kane and Roach mechanical hammer. High yellow heat, off the shelf a36 hot rolled, numbers are the average of 3 tests.
5 blows- .877 inch
10 blows- .721 inch
I run this hammer at 200bpm, slower than optimal for drawing but I use a fair number of top tools so need a little better control. 6.25in max. of daylight between dies when adjusted for 1in. stock.