An end effector assembly includes first and second jaw members pivotable between spaced-apart and approximated positions. The first and second jaw members include first and second proximal flanges, respectively. A pivot pin couples the proximal flanges of the jaw members to one another. The pivot pin includes a body and a head. The body is coupled to the first proximal flange. The head defines a first ramped surface configured to slidably contact a second ramped surface of the second proximal flange. In the spaced-apart position of the jaw members, the first and second ramped surfaces are oppositely disposed such that a maximum clearance is defined between the first and second proximal flanges. In the approximated position of the jaw members, the first and second ramped surfaces are similarly disposed such that a minimum clearance is defined between the first and second proximal flanges.