Fig 2.23 illustrates the recess pin which make through holes is supported at both ends, but the recess may usually contain a small particle of flash prior to a new molding cycle. If the pin entering the recess butts against this hard flash, the pin may break. This method is most frequently used in molding holes. The strength of the pin making the hole is affected by the ratio of its depth to its diameter which called"slenderness ratio"or depth to-diameter ratio.
