Abstract: An injection mold was designed in the cavity layout and internal thread demolding modes for a pen tip part. The mold action consists of the thread sleeve rotation, rotation block and linear translation along the axis of part, which realized a whole internal thread in the pen tip part. Moreover, the four-columns and multi-rows layout and gear transmission were selected for this multi-cavities injection mold when designing, thus making this mold more compact. On the basis of this design idea, an injection mold with 24 cavities for the pen tip part was designed and manufactured. The practical production indicated that the assembly line has a high automation by using this mold and also exhibited a high efficiency in mass production.

Key words: injection mold, pen tip part, thread demolding, multi-cavity layout