the smallest aperture 0.3mm And an outer diameter0.6mmTo ensure that not less than unilateral solder ring 0.15mm.I will be the Secretary for keying hole ( Pad ) be increased to compensate 0.15mm So to make up the production process aperture hole wall because copper sink caused by smaller, while for vias (Via) will not be compensated, the design Pad and Via can not be mixed, or because of the different components of the compensation mechanism caused you difficulty inserted into the printed conductor width tolerance internal standard ± 10%