space not shown between the inner rim 14 and the outer contour 28 defines the shape of the part in this example tool the shape is that of a cylinder having one end sealed in an injection mold tool the space is in communication with a supply of material to be molded into the part under pressure by means of a sprue and gate not shown provided in the cavity portion 10 or the core portion 24 as is well known in the industry as will be understood by those skilled in the art the part could have any inner and outer contour desired the contours shown in fig1 4 are only by way of illustration one method for calculating the theoretical heat transfer between the part and the fluid in an internal channel in the tool is finite element analysis iterative calculations of the theoretical heat transfer by finite element analysis can be rapidly accomplished by using a computer aided design program one example of such a program is c mold to calculate the theoretical heat transfer within the cavity portion 10 of the example tool by finite element analysis using c mold an operator must first input a set of data points which define the inner and the outer contour of the part next data points which.