Abstract: Described herein is a plunger of an injection molding machine, comprising a plunger body; a plunger tip that is a separate element from the plunger body and comprises an end surface configured to directly contact a molten material used in injection molding in the injection molding machine; wherein thermal conductance across the end surface of the plunger tip may be adjustable by moving the plunger tip relative to the plunger body such that temperature of the plunger tip may be adjusted during injection molding. When this plunger is used to injection molding of a BMG, it allows reduction of formation of crystalline phases near the plunger tip and allows replacement of the plunger tip without replacement of the plunger body.