The EXPRESS information models on these pages were the latest versions available on the EXPRESS archive at the time of this release. Newer versions of these files may be available, as well as files for other STEP parts. Check the SC4 EXPRESS Archive for the latest:

        http://www.steptools.com/sc4/archive/

STEP standards are copyrighted by ISO, but ISO permits the EXPRESS listings from these documents to be freely distributed. The complete standards documents are available for purchase through the ISO Central Secretariat at:

        http://www.iso.org/