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Changing a Name

April 18, 2010

Filed under: additive manufacturing — Terry Wohlers @ 08:29

Old habits die slowly. Case in point: Transitioning to the term “additive manufacturing.” That’s now the official name of what some refer to as rapid prototyping, freeform fabrication, and a host of other names. Additive manufacturing (AM) is the official name …. according to who? ASTM International F42 Committee on Additive Manufacturing Technologies. The group put a lot of thought into it, first selecting AM as the favorite for the name of the committee. It then carefully defined it. The term was not my first choice, but I made the decision to accept, use, and encourage others to use the term, which was decided by consensus—a standards-making process that ASTM has refined over the past 100 years. I decided that if scores of professionals across four continents can agree on it, the term should hold weight and be taken seriously.

Defining AM required input, changes, constructive argument, more changes, etc., etc. Eventually, the members of F42 voted on and approved the following:

Additive manufacturing (AM), n—process of joining materials
to make objects from 3D model data, usually layer upon layer,
as opposed to subtractive manufacturing methodologies.
Synonyms: additive fabrication, additive processes, additive
techniques, additive layer manufacturing, layer manufacturing,
and freeform fabrication.

The definition includes all applications of the technology, including the making of models, patterns, and prototypes for form, fit, and function; mold, die, fixture, and assembly tooling; and custom and limited-edition products, replacement parts, and short-run and series production. Rapid prototyping is the most popular application of AM technology, but it is only one of many.

I hope you can be a part of this change. If you’re uncertain, ask, “Do I want to be a part of the past or a part of the future?” Someone once said that the use of “rapid prototyping” as the generic term is so “1990s,” which is true. Join the 21st century and also consider joining the ASTM F42 standards effort. The group has identified, defined, and approved 28 AM-related terms, but this is only a start. If terminology is not your thing, consider getting involved in one of the other F42 activities. They include the development of standards around test methods, processes, materials, and design (including data/file formats). Retire old habits and help advance the additive manufacturing industry to a new level.


  1. The SME uses the term “Direct Digital Manufacturing.” Has this term been considered to fall within the AM umbrella? These professional associations should consider using the ASTM terminology.

    Steve Fernandes

    Comment by stevefernandes — April 26, 2010 @ 11:01

  2. The ASTM F42 Committee considered “direct digital manufacturing,” but chose not to recognize it. I also hope that professional associations choose to adopt the industry standard terms and definitions published by ASTM International. Note that this standards initiative was driven by a cooperative effort between ASTM International and the Society of Manufacturing Engineers.

    Comment by Terry Wohlers — April 26, 2010 @ 11:40