This is a simple hole size test block for testing Imperial hole sizes between 0.120" and 0.139" in 0.001" increments. The sizes are the original sizes. Actual printed hole sizes are usually slightly smaller.
I designed it to test how much closure would occur in shaft holes for a clock I am designing. It lets me know how much a hole should be upsized for a loose or tight fit.
What I found out is that increasing the hole size by 0.003" would produce a reasonably tight press fit. 0.004" oversize can be inserted by hand with some pressure. 0.005" oversize is an accurate sliding fit. Anything larger has increasing amounts of slop.