Snap to Symmetry
Mode
Edit Mode
Menu
Mesh ‣ Snap to Symmetry
The Snap to Symmetry tool lets you snap a mesh vertices to their mirrored neighbors.
This can be caused by accident when editing without X Mirror enabled. Sometimes models imported from other applications are asymmetrical enough that mirror fails too.
Direction
Specify the axis and direction to snap. Can be any of the three axes, and either positive to negative, or negative to positive.
Threshold
Specify the search radius to use when finding matching vertices.
Support for blending mirrored locations from one side to the other (0.5 is an equal mix of both).
Center
Snap vertices along the center axis to zero.