I looked and there's a ton of STEP formats. STEP was to avoid the cacophany of IGES, where everyone 'supported' IGES but used limited and unique subsets, by specifying test suites. Don't support the suite, can't claim compatibility.
Apparently the STEP group gave that up in favor of suppliers just vouching for it. It was a result of trying to make STEP all things to all people for the sales value, but it overextended the ability of the standards orgs to create the tests.
Now it falls under ISO 10303. From Wikipedia, just the mechanical top of the iceberg:
Mechanical:
- AP 201, Explicit draughting. Simple 2D drawing geometry related to a product. No association, no assembly hierarchy.
- AP 202, Associative draughting. 2D/3D drawing with association, but no product structure.
- AP 203, Configuration controlled 3D designs of mechanical parts and assemblies.
- AP 204, Mechanical design using boundary representation
- AP 207, Sheet metal die planning and design
- AP 209, Composite and metallic structural analysis and related design
- AP 214, Core data for automotive mechanical design processes
- AP 235, Materials information for the design and verification of products
- AP 236, Furniture product data and project data
- AP 242, Managed model based 3d engineering (under development)
From ISO on ISO-10303-203, 400 HTML pages, 198 swiss francs, ~$220 US :
The following are within the scope of ISO 10303-203:2011:
- products that are mechanical parts and assemblies;
- product definition data and configuration control data pertaining to the design phase of a product's development;
- representation of an instance of a part in an assembly through its usage in a sub-assembly;
- three-dimensional shape representations of a part that includes:
- geometrically and topologically bounded wireframe models;
- geometrically bounded surface models;
- topologically bounded solid models with facetted, elementary and advanced faces;
- non surface bounded solid models including constructive solid geometry, curve swept and other swept solids, thickened face solid;
- solids with construction history;
- topologically bounded manifold surface and subsurface and non manifold surface models;
- topologically bounded compound models;
- geometric validation properties to allow the translation of geometric shape representations (advanced boundary representation and faceted boundary representation solids) to be checked for quality;
- geometric and dimensional tolerances applied to geometric shape representations;
- materials and their composition of chemical substance;
- composite material structure and shape;
- catalogue data characterized by property value pairs;
- three-dimensional presentation of product data:
- arranging geometric elements in layers and groups and assigning colours;
- presentation styles for points, curves, surfaces and sections, including hatching and tiling;
- saved views of particular camera positions and sections;
- textual annotation and notes applied to geometric elements;
- presentation of geometric and dimensional tolerances;
- technical drawings as two-dimensional presentation of product data.
This won't be enough. See the other related specs, some needed to tell how to read this one:
http://www.iso.org/iso/home/store/catalogue_ics/catalogue_ics_browse.htm?ICS1=25&ICS2=040&ICS3=40&
