A family mold is a mold which combines different part numbers into the same mold base. There can be multiple cavities of the different part numbers. Family molds can often have a mold building cost advantage over molds dedicated to a single part number.
An common usage case is combining the two halves of a housing into family mold. Case halves are almost always purchased in sets which makes running them together a good option. Often a battery door or cover may be included in the family mold. They may not always be run when the case halves are run so a shut-off runner is almost always included which allows one or more cavities to be turned off during production.
Family molds are often recommend over dedicated molds for parts with moderate production volumes, where dedicated multi-cavity molds would not be cost effective. They do have drawbacks and there are many cases where they just won't work. Look over the decision factors below to get an idea if a family mold is for you.
APP will always advise and assist you on making these decisions and can easily supply quotes for all variations.