In the Clearance tab, you can define an initial clearance value and a contact
direction for a contact pair.
The Contact Manager can only be used to create a clearance definition for contact
pairs that have one main-secondary pair. If a contact pair has more than one
main-secondary pairs, then clearance has to be defined for each main-secondary pair
in the Entity Editor or in the Interfaces panel.
The Clearance tab is enabled when a main and secondary surface are selected in the
Define tab, and the Small sliding and Clearance check boxes are selected in the
Parameter tab.