Dimensional Tolerances and GD&T

There’re a lot of guides for the right fits you can choose before you proceed to manufacturing… But when it comes to GD&T it’s so damn hard to specify a certain value… A colleague engineer has to find a similar product from a company which has the 2D drawing and just copies it…

I told him that he should check the different tolerances of different cutting tools in different machines. (so for example : an end mill from a company X that has a diameter of Y, has a max tolerance of Z). But he couldn’t find that.

Am I right in my suggestion?, and if Im right, is there a catalog of what I’m looking for?