The definition of an antique is an item that is 100 years old. If one is importing antiques into South Africa you are not required to pay duty on them. In order for customs to clear these goods under the antique tariff heading you will need a clearance certificate from the South African Antique, Art and Design Association (SAADA) confirming that the goods are antique.
In order to obtain this certificate contact the SAADA office or email a list of the items that you will be importing. This should include a description of the item, the country of origin as well as the approximate date that it was made.