Hole recommendations
Elprint recommends that finished holes are at least 0.3 mm (12 mil) larger than the component lead to be mounted in the hole as this gives sufficient space for insertion and solder penetration.

Pad recommendations
Pad diameters must be at least 0.3 mm (12 mil) and preferably 0.5 mm (20 mil) larger than the hole diameter (annular ring).

Solder mask recommendations
Solder mask diameter should be at least 0.15 mm (6 mil) and preferably 0.25 mm (10 mil) larger than the pad diameter.

The above recommendations give the following dimensions in the diagram as below:

Item Comment
A Component lead diameter.
Rounded up to nearest 0.1 mm.
For via holes is A = 0.
B A + 0.3 mm (12 mil).
C Minimum A + 0.6 mm (24 mil).
Preferably A + 0.8 mm (31 mil).
D Minimum A + 0.75 mm (30 mil).
Preferably A + 1.05 mm (41 mil).