A Neutral file is a formatted text file containing information about parts and assemblies created in Creo. The Creo application formats part geometry data so that other software systems can easily read it and a wide variety of applications can use it. You can create neutral files from parts and assemblies.

Part Neutral files contain information about the part geometry and the features of the part. Assembly Neutral files contain information about how the parts and subassemblies are placed in the assembly and general information about the component parts. When you create a Neutral file from an assembly, the system generates a Neutral file for each component part, and the assembly Neutral file contains a list of the individual part file names.

If the part or assembly has faceted data, the faceted data is exported to the Neutral file format.

The Neutral file contains information about parts and assemblies which is not supported by IGES (such as attributes). With a Neutral file, you can access this information and use it to create interfaces with other programs.

You cannot open in the earlier versions of Pro/ENGINEER parts and assemblies created in the current version of Creo. However, you can use the Neutral file format to collaboratively share data with the earlier versions of Pro/ENGINEER. See the Help module Associative Topology Bus for more information.

An assembly Neutral file contains a list of the component assembly members and the mass properties of the assembly, as well as the current revision number of the assembly.

Part Neutral files include the feature and geometry data for one part only. Each part Neutral file contains one part entity, one or more feature entities, and as many surface and edge entities as are needed to describe the part geometry. A part Neutral file can also contain other entities such as associated text files and mass properties.

Neutral files follow the naming convention <objectname>.neu.#, where <objectname> is the name of the part or assembly the system uses to generate the data file and # is the version or index of the Neutral file created.

In order to create a Neutral file, you must first retrieve the part or assembly.