A mold for producing a product with internal flutes is provided. The mold includes a mold body that defines a cavity and a shaft in proximity to the cavity. A pin assembly is receivably engaged in the shaft of the mold body. The pin assembly includes a pin with a grooved portion that has at least one helically shaped groove, a sleeve surroundingly disposed about a portion of the pin, and means to allow rotation of the pin. A gap is defined in between a portion of the walls of the shaft of the mold body and the grooved portion of the pin and the gap is partially terminated by a portion of the sleeve. A method of molding is also provided.