One of my plans for a bench is to include a leg vise.

My design uses a parallel bar at the bottom of the vise to set with a pin. Most of these have three rows of holes for inserting the pin. Part of my plan is to build a pin setting system so a person doesn't have to reach down to set the pin.

My question is what is the distance between centers from row to row?

From looking at images on line, one showed 2cm or just a mm over 3/4". That seems like it could cause vertical racking at times.

jtk