There are currently two options:
Radial Leads On small holes the Leadin will come from the center of the circle or one of the centers of the slot. On slots we try to attach the the "ends" so that a bolt can slide freely within the slot without catching on any lead attachment defect.
Arc Leads A semicircular arc will attach tangentially. Again, on slots, the end is preferred.
NOTE Pierce Centrally On Small Holes setting takes preference where applicable, see below.
 Arc Leads |
 Radial Leads |
 Pierce Centrally Takes Precedence |