A mold device is described for use in a mold having a plurality of tread molding segments. Each tread molding segment has an end face for mating with an adjoining segment. The mold device includes a piston located on the segment end face and is actuated by the opening and closing of the mold. Each of the mold segments further includes a retractable blade assembly having a first and second chamber; wherein the piston is positioned within the first chamber and having a plunger end in communication with a temperature sensitive block of material and a spring. The first chamber is in fluid communication with a second chamber, wherein said second chamber further comprises a retractable blade mounted within a blade collar wherein the blade collar is slidably received within said second chamber; said second chamber further comprises a temperature sensitive block of material and a spring.