The hole size designed should be at least 0.1 mm bigger than the pins of components.

A common mistake made by lots of customers. See below picture. The pins size is square 

And engineer just measure the length and width of pin, which is incorrect.

We should measure the diagonal line space of the pin, and the holes size should be 0.1mm larger than that.

Usually, when Linked Electronics’ engineers make the production gerbers,

the through holes size will be increased by 0.15mm,that is what we call compensate the holes.

Because there will be copper inside the PTH, that’s why we have to compensate the holes.

If Linked Electronics does not compensate the DIP holes, and the holes size is smaller than your designed size, that’s our responsibility.

And PTH tolerance is +/-0.075mm at Linked Electronics.