A tire mold and a molding device for forming a sunken groove, sipe in a tire is provided. The molding device molding device comprises a flexible member and a blade element, the flexible member having a distal end for mounting to a tire mold, a radiused midsection and a second end, wherein a portion of the second end is embedded within the blade element, the blade element having a lower surface with a cutout to allow bending of the flexible member.