The following settings are recommended up to CATIA V4.2.5 with COM/STEP 4.3.1.0 and CoCreate Modeling 16.5.

CATIA V4 (T-Systems) - System

• No elements should be placed in NOSHOW/NOPICK.
• Model should be cleaned of all unused information, because the translator exports the complete content of CATIA-parts.
  • Delete:
  • Unused DETAILS (in all workspaces) 
  • Unused elements from NOSHOW (in all workspaces)
  • Drawings
• Update SOLID-M into SOLID-E with CATSOE utility.
• Perform SOLIDE/UPDATE, also if message UPDATE ALREADY DONE appears. (Regeneration removes inconsistencies.)
• Generate Volumes from SOLID-E and delete SOLID-E in all workspaces. (Geometry is still exported as a solid in STEP.)
• Scaled and mirrored dittos (EXPLODE function) should not be used.
• Before export elements of special CATIA modules (e.g. PIPING, BUILDING DESIGN) need to be converted to STEP conform elements.
• Use CATCLN.
• Assembly structures in SETs should be transferred to DETAILS.
• Link all SETs if possible (SETS -> LINK).
• Solids/Volumes consisting of separate Bodies should be avoided.
• Objects used for Boolean operations should show good penetration.

CATIA V4 (T-Systems) - STEP Preprocessor

• The COM/STEP STEP Processor can be used in batch, interactive and Java mode. The following descriptions refer to the Java GUI.
• Menu STEP:
  • Select AP214 Version IS
  • Conformance Class: CC2 for geometry and CC20 for drawings
  • Select Product Structure S3: Item_Definition_Structure for assemblies
  • Geometry and topology: select G2, G3 and G5, do not select G4 and G7
• Menu Conversions 
  • Choose Solid as Target modeling system.
  • INDEX and DATA size should always be set to generous values (50000, 200000).
  • Exporting DETAIL/DITTO creates STEP assemblies with the top level product named after the CATIA model. 

STEP File

• STEP files using either version (CD or DIS) can be imported.
• The STEP filename including path should not exceed 41 Characters.
• The STEP filename should not contain: equal sign (=), colon (:), semicolon (;), asterisk (*), question mark (?), quotation marks (""), or comma(,);
• There must be no spaces in the STEP filename.
• The extension *.step of the STEP files must be renamed to *.stp.

OneSpace Designer- STEP Postprocessor

• The properties for STEP import can be found in the file -> open -> options dialog
• Set the accuracy to automatic (default) to use the accuracy of the STEP file.
• If the accuracy is customized, make sure that the accuracy setting is the same or less than the accuracies setting used to generate the part being loaded.
• When associated messages are returned during the import of the STEP file the accuracy should be adjusted.
• If a product with multiple bodies is imported, Solid Designer creates an assembly.
• Blended edges are not recognized as such, and it is not possible to modify blends using standard OneSpace Designer. 
• The import log file "step_load_log" gives further information.

OneSpace Designer – System

• Shaded view is helpful and gives a first impression of the model quality.
• To ensure the model quality is OK a complete model check should be performed.