Be attention please, the hole in workpiece means a pin insert or core in the mold, the pin will be subject to pressure which may cause pin breakage and wear. If the depth is no more than 2 times
diameter,the pin can be supported only at one end, as shows in Fig. 2. 20. If the hole diameter is less
than 0.062in, the depth of hole should less than ID If the diameter is more than 0.062in, the depth of hole should no more than 2D. If the length is greater than 4 times diameter, the hole should be through Fig 2.21 to Fig 2.23 list holes molded by slender pins with the various types of molding methods. If the depth to diameter ratio is over 2, the following is what we can do. Holes may extend entirely through the workpiece, in which case the core or pin may be supported at both ends. Fig. 2. 21 shows a slender hole molded by one pin which is supported at one end and withstand in other end. The height of hole is less than 2D for compression molds, 6D for transfer molds or injection molds.
Fig.2.22 illustrates a slender hole molded by two pins. The height of hole is less than 6D for compression molds, 1SD for transfer molds or injection molds. If a slender hole molded by two pins
as Fig 2.22, that may have a misalignment between the two pins. It may be ditticult to assembly the
workpiece with other part, namely a bolt or shatt Provision should be made for the misalignment of cavity and plunger and the possiblity of the pin's bending. If either misalignment or bending occurs, the companion part may not go through the hole.
