The present disclosure provides a molding element for a mold used for manufacturing a tread of a tire having a plurality of contacting element, a plurality of grooves and a connecting member connecting two side faces of adjacent contacting elements, the molding element having a molding surface and a rib for forming the groove between adjacent contacting elements, at least two rib side faces, the rib having a notching portion, the guiding member having a guiding slit extending from one of the two opposite side faces to the other of the two opposite side faces through the guiding member and radially from the top face, at least one of faces of the notching portion is provided with a means for keeping the guiding member in place in the notching portion.