Because of the apparent blurred line between the two, those who do not encounter this technology might not understand the difference between additive manufacturing and 3D printing. However, there is a distinction between these two labels, and their definitions have been standardized officially.
According to ISO/ASTM 52900:2015 - Additive manufacturing - General principles – Terminology, these two terms are defined as:
3D Printing: “fabrication of objects through the deposition of a material using a print head, nozzle, or another printer technology”
Additive Manufacturing (AM): “process of joining materials to make parts from 3D model data, usually layer upon layer”
The standard further differentiates the two by separately defining the devices that perform each task:
3D Printer: “machine used for 3D printing”
Additive Manufacturing System: “machine and auxiliary equipment used for additive manufacturing”
From these definitions, it is clear that the terms do refer to two different idea, but 3D printing can be used to refer to any 3D-printed practice, even additive manufacturing. However, additive manufacturing only refers to the advanced method of 3D printing materials “layer upon layer,” and not the simpler process of 3D printing a single basic item.
Therefore, much like the classic square and rectangle counterexample in mathematics, it could be said that all additive manufacturing is 3D printing, but not all 3D printing is additive manufacturing.
However, as previously noted, these two terms are often used interchangeably, with additive manufacturing being avoided almost entirely, unless it is referenced in industrial applications. 3D printing is certainly a label that has caught on with the public far more easily, and, even when referring to advanced additive manufacturing of parts or products, people call the process 3D printing.
While the term additive manufacturing is correct for these processes and is used often for technical purposes, it was anticipated during standardization that AM-produced materials would be called 3D-printed materials. In fact, it is stated in ISO/ASTM 52900:2015 that 3D printing is a term “often used in a non-technical context synonymously with additive manufacturing.”
Ultimately, 3D printing is technically correct when referring to any of these processes, but it is not as precise as additive manufacturing when describing layered 3D printing activities. However, while additive manufacturing is often favored as a technical term in industry, the usage of this technology is still incredibly new, and it is possible that the standard terminology can change and more distinctly define itself as it finds more widespread use.
Browse the ANSI Webstore for more additive manufacturing standards.