The standard file format for additive manufacturing (AM) and 3D printing has been updated. The file used in AM is quite possibly the most important aspect of the process, since it determines the entire layout of the fabricated product. The current standard, as addressed in ISO/ASTM 52915:2020 – Specification for Additive Manufacturing File Format (AMF) Version 1.2 is an enhancement of the Additive Manufacturing File Format (AMF).
The standard AMF file addressed in ISO/ASTM 52915:2020 is intended to replace the use of the STL file, which, for the past three decades, has lasted as the industry standard for transferring information between design programs and additive manufacturing. However, the newer AMF file, which was introduced as the official standard in 2011, better meets the current needs of additive manufacturing and 3D printing technology.
The STL file format was originally developed as part of the CAD package for early stereolithography technology, and although it has since been widely adopted for 3D printing, it was never actually recognized as an official standard by any standardization body. An STL file defines only surface mesh, giving no provisions for representing color, texture, material, substructure and other properties of the object that the file is created to manufacture.
However, additive manufacturing has uses in consumer products, architecture, medical technology, and the aerospace industry, among many other groups. Between all of these, a plethora of objects and equipment has been additive manufactured in highly customizable ways. The AMF format is XML-based, which makes it highly compressible and easy to read, write, and process. AMF is a format that allows for the inclusion of many aspects that STL files cannot address, including colors, units, and materials.
In addition, since AM has uses is a variety of industries, it is necessary that the standard file format used is highly interoperable. With the XML-based format, designers can include as much information as possible in the standard AMF file.
ISO/ASTM 52915:2020 acknowledges that the needs of the additive manufacturing industry will change as the technology continues to grow. Because of this, the specifications covered in the document are intended to make the AMF format forwards compatible to allow for the incorporation of new features. It is even backwards compatible with STL files, and conversion between the two can be accomplished without loss of information.
A W3C XML schema definition (XSD) for the AMF that is covered in this document is available from ISO (http://standards.iso.org/iso/52915) and from ASTM (www.astm.org/MEETINGS/images/amf.xsd).
If you would like to learn more about other additive manufacturing standards, please refer to this post: Additive Manufacturing Standards