Abstract: An underwater pelletizer and heat exchanger die plate combination for solidifying molten polymer entering the machine at one end and cutting the solidified fibers into small pieces or pellets. A die plate incorporating steam heated tubes allows molten plastic under high pressure to be forced therethrough into a water bath. Two or more rotating knives within the water bath rotating on the face of the die plate sever or cut up the solidified plastic into small pellets. A quick access coupling is provided for the water bath compartment and a floating ball bearing adjustment means for varying the distance between the rotating knives and the die plate is provided to permit very accurate variation of the distance between the knives and the die plate surface. An overall support frame is provided for the entire structure which is movably mounted on rollers which are also adjustable.