A bone plate includes a bone-contacting surface, an upper surface opposite the bone-contacting surface, and a hole having a circumference and extending from the upper surface to the bone-contacting surface. The hole includes a first portion having a plurality of substantially parallel lips, each lip extends around the circumference of the hole and defines a diameter of the hole. The diameters of the hole, as defined by the lips, decrease in a direction from the upper surface to a center of the hole and increase in a direction from the center of the hole toward the bone-contacting surface.
