1,The floor of the occlusal rest seat should be apical to the marginal ridge and occlusal surface should be concave or spoon shaped.

    2,It should be as long as its wide,and the base of the triangular shape should be at least 2.5mm for both molars and premolars.

    3,The outline form of an occlusal rest seat should be a "rounded" triangular shape with the apex toward the center of the occlusal surface.

    4,The marginal ridge of the abutment tooth at the site of the rest seat must be lowered to permit a sufficient bulk of metal for strength and rigidity of the rest and minor connector.

    5,The angle formed by the occlusal rest and the vertical minor connector from it originates should be less than 90 degrees.