Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.



The ISO 10303 Standard for Product Model Data, also known as STEP (STandard for the Exchange of Product model data), is a foundational standard for integrating engineering and manufacturing systems today and is broadly used for sharing engineering and manufacturing data within organizations and across supply chains.  NIST has a long standing history since the 1980's of engagement with developing this series of standards first through the Manufacturing Engineering Lab, more recently in the Systems Integration Division in the Engineering Lab, and now in the Smart Connected Manufacturing Systems Group.

NIST served as the original secretariat for STEP in the 1990's, providing an electronic document repository and running listservs in the early days of the Internet before the World Wide Web.  More recently we were instrumental in developing and promoting deployment of the latest in the STEP series of standards AP242 edition 2, which has now been deployed by all major computer-aided design (CAD) vendors. The set of test cases from the MBE PMI Validation and Conformance Testing Project and the STEP File Analyzer and Viewer tool play an instrumental role in the quick adoption of this new addition to the standards.

NIST is a member of PDES, Inc., a U.S. industry consortium that helps develop and implement STEP standards.


Current research related to the ISO 10303 STEP standards takes place in the Digital Thread for Manufacturing project.  Past research took place in the Extended Digital Thread, Product Definitions for Smart Manufacturing, and the Digital Thread for Smart Manufacturing projects.

Follow the links to the left about NIST research and software related to the ISO 10303 STEP standards.

NIST continues its support of key leadership roles in ISO TC 184/SC 4 Industrial Data: including a standards project manager and editor, the STEP Product Modeling and Resources Working Group Convener, and the Geometric and Topological Representation Team Lead.  NIST supports an integrated development environment to automate the publication of STEP resource parts.  Development of the fourth edition of ISO 10303-242 (AP242e4) started in FY22.  NIST serves on the AP242e4 Steering Committee, supports research to underpin new methods and models for the use of GUIDs, hybrid geometric modeling and overall coherence of ISO 10303-42 Geometry and Topology, models for new semantic PMI, and harmonization of the ISO 10303 composite structures data representations with the ASME composite structures practice standards.

The STEP File Analyzer and Viewer is used by the CAx-IF to check for conformance to recommended practices for implementations of STEP in CAD software.


These are some of the more commonly used STEP standards.

Created March 9, 2021, Updated January 9, 2023