The bolster plate has through drilled holes that create pin pattern for die pins to run on top of the die cushion that provides ring holding force. Sometimes instead of seperate holes for each of the die pins, bigger cutout is made and then die pins can be placed anywhere within this cutout. In both cases, the die cushion pin pad should cover the whole area of the pin pattern. If pin pattern is used, it can be custom or follow the industry standard of J.I.C. pin pattern. J.I.C. pattern gives equal 3" spacing between pin holes for smaller presses. This spacing increases to 6" for bigger size presses. This standard pattern is commonly used and ideal for job shops that might get new die sets that most probably will require this pattern. All bolster plate mounted die cushions are designed not to interfere with standard J.I.C. pattern.
Refer to the PDF file below for the drawing of J.I.C. pattern pin holes as well as standard bolster mounting rods locations for all cushion models.