ISO 4709给出了机械工业中用作垫圈的复合软木的分类系统。它提供了一种指定或描述相关属性的方法。 由于并非所有有助于垫圈性能的特性都包括在内，因此该系统的使用仅限于根据规定要求选择材料。

ISO 4709 gives a classification system for composition cork intended to be used as gaskets in the mechanical industry. It provides a means for specifying or describing the relevant properties. Since not all properties that contribute to gasket performance are included, the use of this system is limited to the selection of materials in accordance with specified requirements.