This invention relates to a method of forming an aperture part and also to a method of manufacturing an element that is to be made up of a number of parts. 
In connection with the forming of parts, particularly by such methods as blow molding, it is often necessary to form apertures in the parts.  In connection with many articles it is difficult to accurately locate the aperture once the part is formed into its final shape. 
It is, therefore, a first principal object of this invention to provide an improved method for forming and aperturing a part. 
It is another object of the invention to provide a method for blow molding and aperturing parts. 
In many instances elements are manufactured from a plurality of parts that are connected together.  One way in which such parts may be assembled is through the use of fasteners such as rivets and/or bolts which press through apertures in their respective parts.  In order to assure a good fit of the final article, the apertures in each part must be accurately located relative to the part in which they are formed and relative to the corresponding aperture in the other part.  Although this may be accomplished by means of holding extremely close tolerances, such accurate forming and machining through the use of close tolerances is many times more expensive than justified. 
It is, therefore, a further principle object of this invention to provide a method for forming parts that are to be assembled together. 
It is a further object of this invention to provide an improved method for accurately locating apertures in each of two parts where the apertures are used to fix the parts together.