Mine is generally around 1.5,but i have lots of wear in the machine and when i put the blade in i lift up on the blade to to erase any play in the arms before i tighten the blade clamp.I tighten the top arm last.I hold the blade with my thumb and index finger, Rest my middle finger on top of the top arm for leverage,raise the blade up and tighten the thumb screw with my right hand.