OK...one more time
The "Outside Circle" routine takes the programmed circle diameter then offsets the toolpath to the outside and creates lead ins/outs. The finished part is a boss of the programmed size.
The "Inside Circle" routine takes the programmed circle diameter then offsets the toolpath to the inside and creates lead ins/outs. The finished part is a Hole of the programmed size.
The "On Circle" routine takes the programmed circle diameter then centers the toolpath to it without leads. The finished part is a Circular Slot of the programmed size.
The "Pocket Circle" routine takes the programmed circle diameter then offsets the toolpath to the inside and clears out the interior of the programmed circle. The finished part is a circular pocket of the programmed size.
The "Arc" routine takes the programmed circle diameter with start and end points then centers the toolpath to it without leads. The finished part is a Circular Arc Slot of the programmed size.
Finally....slotted holes/arcs can't have leads, but bosses and holes can benefit from them. I really hope this clears it up :drowning: