Tolerance coning

Tolerance coning is when you make a part or a machine that is exactly the same shape it needs to be, but it has a little bit of room for things to fit into it that are not exactly the same shape. It's like when you fill a cup with a bunch of different shaped marbles. The marbles might be different sizes, but they are still able to fit in the cup because the cup has a little bit of extra room. That extra room is called tolerance and it helps make sure things fit together correctly.