ISO/ASTM FDIS 52900

Additive manufacturing -- General principles -- Fundamentals and vocabulary

Fabrication additive -- Principes généraux -- Fondamentaux et vocabulaire

General Information

• Status: Published
• ICS: 01.040.25 - Manufacturing engineering (Vocabularies)
• ICS: 25.030 - Additive manufacturing
• Technical Committee: ISO/TC 261 - Additive manufacturing
• Drafting Committee: ISO/TC 261/JG 51 - Joint ISO/TC 261-ASTM F 42 Group: Terminology
• Current Stage: 5020 - FDIS ballot initiated: 2 months. Proof sent to secretariat
• Start Date: 19-Aug-2021
• Completion Date: 19-Aug-2021

RELATIONS

• Revised: ISO/ASTM 52900:2015 - Additive manufacturing -- General principles -- Terminology
• Effective Date: 23-Sep-2017

Standards Content (sample)

FINAL
INTERNATIONAL ISO/ASTM
DRAFT
STANDARD FDIS
52900
ISO/TC 261
Additive manufacturing — General
Secretariat: DIN
principles — Fundamentals and
Voting begins on:
2021­08­19 vocabulary
Voting terminates on:
Fabrication additive — Principes généraux — Fondamentaux et
2021­10­14
vocabulaire
ISO/CEN PARALLEL PROCESSING
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/ASTM FDIS 52900:2021(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN­
DARDS TO WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS. ISO/ASTM 2021
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ISO/ASTM FDIS 52900:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO/ASTM International 2021

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be

reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on

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ISO copyright office ASTM International
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Published in Switzerland
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ISO/ASTM FDIS 52900:2021(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

3.1 General terms ........................................................................................................................................................................................... 1

3.2 Process categories ................................................................................................................................................................................ 2

3.3 Processing: general ............................................................................................................................................................................. 4

3.4 Processing: data ..................................................................................................................................................................................... 5

3.5 Processing: positioning, coordinates and orientation .......................................................................................... 7

3.6 Processing: material ........................................................................................................................................................................10

3.7 Processing: material extrusion ..............................................................................................................................................11

3.8 Processing: powder bed fusion ..............................................................................................................................................12

3.9 Parts: general .........................................................................................................................................................................................14

3.10 Parts: applications.............................................................................................................................................................................14

3.11 Parts: properties .................................................................................................................................................................................14

3.12 Parts: evaluation .................................................................................................................................................................................16

Annex A (normative) Identification of AM processes based on process categories and

determining characteristics ..................................................................................................................................................................17

Annex B (informative) Basic principles ..........................................................................................................................................................20

Bibliography .............................................................................................................................................................................................................................25

Alphabetical index .............................................................................................................................................................................................................26

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ISO/ASTM FDIS 52900:2021(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non­governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/ patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso .org/

iso/ foreword .html.

This document was prepared by ISO/TC 261, Additive manufacturing, in cooperation with ASTM

Committee F42, Additive Manufacturing Technologies, on the basis of a partnership agreement between

ISO and ASTM International with the aim to create a common set of ISO/ASTM standards on additive

manufacturing.

This second edition of ISO/ASTM 52900 replaces the first edition (ISO/ASTM 52900:2015), which has

been technically revised. The main changes compared to the previous edition are as follows:

— new and modified terms and definitions;
— abbreviations added for seven process categories;

— new annex for the specification of AM processes based on process categories and determining

characteristics (Annex A).

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/ members .html.
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ISO/ASTM FDIS 52900:2021(E)
Introduction

Additive manufacturing (AM) is the general term for those technologies that successively join material

to create physical objects as specified by 3D model data. These technologies are presently used for

various applications in engineering industry as well as other areas of society, such as medicine,

education, architecture, cartography, toys and entertainment.

During the development of additive manufacturing technology, there have been numerous different

terms and definitions in use, often with reference to specific application areas and trademarks. This

is often ambiguous and confusing, which hampers communication and wider application of this

technology.

It is the intention of this document to provide a basic understanding of the fundamental principles

for additive manufacturing processes, and based on this, to give clear definitions for terms and

nomenclature associated with additive manufacturing technology. The objective of this standardization

of terminology for additive manufacturing is to facilitate communication between people involved in

this field of technology on a worldwide basis.
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FINAL DRAFT INTERNATIONAL STANDARD ISO/ASTM FDIS 52900:2021(E)
Additive manufacturing — General principles —
Fundamentals and vocabulary
1 Scope

This document establishes and defines terms used in additive manufacturing (AM) technology, which

applies the additive shaping principle and thereby builds physical three-dimensional (3D) geometries

by successive addition of material.
The terms have been classified into specific fields of application.
2 Normative references
There are no normative references in this document.
3 Terms and definitions

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1 General terms
3.1.1
3D printer, noun
machine used for 3D printing (3.3.1)
3.1.2
additive manufacturing, noun

process of joining materials to make parts (3.9.1) from 3D model data, usually layer (3.3.7) upon layer,

as opposed to subtractive manufacturing and formative manufacturing methodologies

Note 1 to entry: Historical terms include: additive fabrication, additive processes, additive techniques, additive

layer manufacturing, layer manufacturing, solid freeform fabrication and freeform fabrication.

Note 2 to entry: The meaning of “additive-”, “subtractive-” and “formative-” manufacturing methodologies is

further discussed in Annex B.
3.1.3
additive system, noun
additive manufacturing system
additive manufacturing equipment
machine and auxiliary equipment used for additive manufacturing (3.1.2)
3.1.4
AM machine, noun

section of the additive manufacturing system (3.1.3) including hardware, machine control software,

required set-up software and peripheral accessories necessary to complete a build cycle (3.3.8) for

producing parts (3.9.1)
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ISO/ASTM FDIS 52900:2021(E)
3.1.5
AM machine user, noun
operator of or entity using an AM machine (3.1.4)
3.1.6
AM system user, noun
additive system user

operator of or entity using an entire additive manufacturing system (3.1.3) or any component of an

additive system (3.1.3)
3.1.7
front, noun

side of the machine that the

operator faces to access the user interface, or primary viewing window, or both
3.1.8
material supplier, noun

provider of material/feedstock (3.6.6) to be processed in an additive manufacturing system (3.1.3)

3.1.9
multi-step process, noun

type of additive manufacturing (3.1.2) process in which parts (3.9.1) are fabricated in two or more

operations where the first typically provides the basic geometric shape and the following consolidates

the part to the fundamental properties of the intended material

Note 1 to entry: Fundamental properties of the intended product material are typically metallic properties for

intended metallic products, ceramic properties for intended ceramic products, polymer properties for intended

polymer (plastic) products and composite material properties for products intended to be made of a composite

material.

Note 2 to entry: Removal of the support structure and cleaning can many times be necessary; however, in this

context, this operation is not considered as a separate process step.

Note 3 to entry: The principle of single-step (3.1.10) and multi­step processes is further discussed in Annex B.

3.1.10
single-step process, noun

type of additive manufacturing (3.1.2) process in which parts (3.9.1) are fabricated in a single operation

where the basic geometric shape and basic material properties of the intended product are achieved

simultaneously

Note 1 to entry: Removal of the support structure and cleaning can many times be necessary; however, in this

context, this operation is not considered as a separate process step.

Note 2 to entry: The principle of single-step and multi-step processes (3.1.9) is further discussed in Annex B.

3.2 Process categories
3.2.1
binder jetting, noun
BJT

additive manufacturing (3.1.2) process in which a liquid bonding agent is selectively deposited to join

powder materials

Note 1 to entry: Identification of different binder jetting processes shall be consistent with the method described

in Annex A.
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ISO/ASTM FDIS 52900:2021(E)
3.2.2
directed energy deposition, noun
DED

additive manufacturing (3.1.2) process in which focused thermal energy is used to fuse materials by

melting as they are being deposited

Note 1 to entry: “Focused thermal energy” means that an energy source (for example laser, electron beam or

plasma arc) is focused to melt the materials being deposited.

Note 2 to entry: Identification of different directed energy deposition processes shall be consistent with the

method described in Annex A.
3.2.3
material extrusion, noun
MEX

additive manufacturing (3.1.2) process in which material is selectively dispensed through a nozzle or

orifice

Note 1 to entry: Identification of different material extrusion processes shall be consistent with the method

described in Annex A.
3.2.4
material jetting, noun
MJT

additive manufacturing (3.1.2) process in which droplets of feedstock material are selectively deposited

Note 1 to entry: Example feedstock materials for material jetting include photopolymer resin and wax.

Note 2 to entry: Identification of different material jetting processes shall be consistent with the method

described in Annex A.
3.2.5
powder bed fusion, noun
PBF

additive manufacturing (3.1.2) process in which thermal energy selectively fuses regions of a powder

bed (3.8.5)

Note 1 to entry: Identification of different powder bed fusion processes shall be consistent with the method

described in Annex A.
3.2.6
sheet lamination, noun
SHL

additive manufacturing (3.1.2) process in which sheets of material are bonded to form a part (3.9.1)

Note 1 to entry: Identification of different sheet lamination processes shall be consistent with the method

described in Annex A.
3.2.7
vat photopolymerization, noun
VPP

additive manufacturing (3.1.2) process in which liquid photopolymer in a vat is selectively cured by

light-activated polymerization

Note 1 to entry: Identification of different vat photopolymerization processes shall be consistent with the method

described in Annex A.
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ISO/ASTM FDIS 52900:2021(E)
3.3 Processing: general
3.3.1
3D printing, noun

fabrication of objects through the deposition of a material using a print head, nozzle or another printer

technology

Note 1 to entry: This term is often used in a non-technical context synonymously with additive manufacturing

(3.1.2) and, in these cases, typically associated with machines used for non-industrial purposes including

personal use.
3.3.2
build chamber, noun

enclosed location within the additive manufacturing system (3.1.3) where the parts (3.9.1) are fabricated

3.3.3
build space, noun

location where it is possible for parts (3.9.1) to be fabricated, typically within the build chamber (3.3.2)

or on a build platform (3.3.5)
3.3.4
build volume, noun
total usable volume available in the machine for building parts (3.9.1)
3.3.5
build platform, noun

base which provides a surface upon which the building of the parts (3.9.1) is started and

supported throughout the build process

Note 1 to entry: In some systems, the parts (3.9.1) are built attached to the build platform, either directly or

through a support (3.3.9) structure. In other systems, such as certain types of powder bed (3.8.5) systems, a

direct mechanical fixture between the part and the build platform is not necessarily required.

3.3.6
build surface, noun

area where material is added, normally on the last deposited layer (3.3.7), which becomes the foundation

upon which the next layer is formed

Note 1 to entry: For the first layer, the build surface is often the build platform (3.3.5).

Note 2 to entry: In the case of directed energy deposition (3.2.2) processes, the build surface can be an existing

part onto which material is added.

Note 3 to entry: If the orientation of the material deposition or consolidation means (or both) is (are) variable, it

may be defined relative to the build surface.
3.3.7
layer, noun
material laid out, or spread, to create a surface
3.3.8
build cycle, noun

single process cycle in which one or more components are built by successive joining of material within

the build space (3.3.3) of the additive manufacturing system (3.1.3)
3.3.9
support, noun

structure separate from the part (3.9.1) geometry that is created to provide a base and anchor for the

part during the building process
Note 1 to entry: Supports are typically removed from the part prior to use.
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ISO/ASTM FDIS 52900:2021(E)

Note 2 to entry: For certain processes such as material extrusion (3.2.3) and material jetting (3.2.4), the support

material can be different from the part material and deposited from a separate nozzle or print head.

Note 3 to entry: For certain processes such as metal powder bed fusion (3.2.5) processes, auxiliary supports can

be added to serve as an additional heat sink for the part during the building process.

3.3.10
process parameters, noun
operating parameters and system settings used during a build cycle (3.3.8)
3.3.11
system set-up, noun
configuration of the additive manufacturing system (3.1.3) for a build cycle
3.3.12
manufacturing lot, noun

set of manufactured parts (3.9.1) having commonality between feedstock (3.6.6), production run (3.3.14),

additive manufacturing system (3.1.3) and post-processing (3.6.10) steps (if required) as recorded on a

single manufacturing work order

Note 1 to entry: The additive manufacturing system can include one or several AM machines (3.1.4) and/or post­

processing machine units as agreed by AM (3.1.2) provider and customer.
3.3.13
manufacturing plan, noun

document setting out the specific manufacturing practices, technical resources and sequences of

activities relevant to the production of a particular product including any specified acceptance criteria

at each stage

Note 1 to entry: For additive manufacturing (3.1.2), the manufacturing plan typically includes, but is not limited to,

process parameters (3.3.10), preparation and post processing (3.6.10) operations as well as relevant verification

methods.

Note 2 to entry: Manufacturing plans are typically required under a quality management system such as ISO 9001

and ASQ C1.
3.3.14
production run, noun

set of all parts (3.9.1) produced in one build cycle (3.3.8) or sequential series of build cycles using the

same feedstock (3.6.6) batch and process conditions
3.3.15
process chain, noun

sequence of operations necessary for the part (3.9.1) to achieve desired functionality and properties

3.4 Processing: data
3.4.1
Additive Manufacturing File Format, noun
AMF

file format for communicating additive manufacturing (3.1.2) model data including a description of the

3D surface geometry with native support for colour, materials, lattices, textures, constellations and

metadata

Note 1 to entry: Additive Manufacturing File Format (AMF) can represent one of multiple objects arranged in a

constellation. Similar to STL (3.4.6), the surface geometry is represented by a triangular mesh, but in AMF the

triangles can also be curved. AMF can also specify the material and colour of each volume and the colour of each

[7]
triangle in the mesh. ISO/ASTM 52915 gives the standard specification of AMF.
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ISO/ASTM FDIS 52900:2021(E)
3.4.2
AMF consumer, noun

software reading (parsing) the AMF (3.4.1) file for fabrication, visualization or analysis

Note 1 to entry: AMF files are typically imported by additive manufacturing equipment (3.1.3), as well as viewing,

analysis and verification software.
3.4.3
AMF editor, noun
software reading and rewriting the AMF (3.4.1) file for conversion

Note 1 to entry: AMF editor applications are used to convert an AMF from one form to another, for example

to convert all curved triangles to flat triangles or convert porous material specification into an explicit mesh

surface.
3.4.4
AMF producer, noun
software writing (generating) the AMF (3.4.1) file from original geometric data

Note 1 to entry: AMF files are typically exported by CAD software, scanning software or directly from

computational geometry algorithms.
3.4.5
STEP, noun
standard for the exchange of product model data

Note 1 to entry: This is an International Standard that provides a representation of product information along

[4]

with the necessary mechanisms and definitions to enable product data to be exchanged. ISO 10303 applies to

the representation of product information, including components and assemblies, the exchange of product data,

including storing, transferring, accessing and archiving.

Note 2 to entry: ISO 10303-238, commonly referred to as STEP-NC, specifies the slicing operation and other

mechanical commands in the AM process.
3.4.6
STL, noun

file format for model data describing the surface geometry of an object as a tessellation of triangles

used to communicate 3D geometries to machines in order to build physical parts (3.9.1)

Note 1 to entry: The STL file format was originally developed as part of the CAD package for the early

STereoLithography Apparatus, thus referring to that process. It is sometimes also described as “Standard

Triangulation Language” or “Standard Tessellation Language”, though it has never been recognized as an official

standard by any standards developing organization.
3.4.7
PDES, noun
Product Data Exchange Specification
data exchange specification using STEP (3.4.5)

Note 1 to entry: Originally, a product data exchange specification developed in the 1980s by the IGES/PDES

Organization, a program of US Product Data Association (USPRO). It was adopted as the basis for and subsequently

[4]
superseded by ISO 10303 STEP.
3.4.8
attribute, noun

characteristic representing one or more aspects, descriptors or elements of the data

Note 1 to entry: In object-oriented systems, attributes are characteristics of objects. In Extensible Markup

[10]
Language (XML), attributes are characteristics of elements (3.3.10).

Note 2 to entry: In the AMF (3.4.1)-file, attributes can, for example, be used to carry notices enabling backwards

traceability to CAD components, or markers that allow track and trace mechanisms for the file.

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ISO/ASTM FDIS 52900:2021(E)
3.4.9
comment, noun
remark in source code which does not affect the behaviour of the program

Note 1 to entry: Comments are used for enhancing human readability of the file and for debugging purposes.

Note 2 to entry: In the AMF (3.4.1)-file, comments can, for example, be used to carry material specification or

notices enabling backwards traceability to CAD components.
3.4.10
element, noun
[10]

information unit within an XML document consisting of a start tag, an end tag, the content between

the tags and any attributes (3.4.8).

Note 1 to entry: In the XML framework of AMF (3.4.1), an element can contain data, attributes structures such as

constellations, as well as including other elements.
3.4.11
facet, noun

three- or four-sided polygon that represents an element of a 3D polygonal mesh surface or model

Note 1 to entry: Triangular facets are used in the file formats most significant to AM (3.1.2): AMF (3.4.1) and STL

(3.4.6); however, AMF files permit a triangular facet to be curved.
3.4.12
surface model, noun

mathematical or digital representation of an object as a set of planar or curved surfaces, or both, that

can, but does not necessarily have to represent a closed volume
3.4.13
3D scanning, noun
3D digitizing

method of acquiring the shape and size of an object as a 3-dimensional representation by recording x,

y, z coordinates on the object’s surface and through software converting the collection of points into

digital data

Note 1 to entry: Typical methods use some amount of automation, coupled with a touch probe, optical sensor or

other device.

Note 2 to entry: In additive manufacturing process chains, 3D scanning can typically be used for generation of

surface models, in situ monitoring, non-destructive testing, as well as verification of the part geometry.

3.5 Processing: positioning, coordinates and orientation
3.5.1
bounding box, noun

orthogonally oriented minimum perimeter cuboid that can span the maximum extents of

the points on the surface of a 3D part (3.9.1)

Note 1 to entry: Where the manufactured part includes the test geometry plus additional external features (for

example labels, tabs or raised lettering), the bounding box may be specified according to the test part geometry

excluding the additional external features if noted. Different varieties of bounding boxes are illustrated in

[8]
ISO/ASTM 52921 .
3.5.2
arbitrarily oriented bounding box, noun

bounding box (3.5.1) calculated without any constraints on the resulting orientation of the

box
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ISO/ASTM FDIS 52900:2021(E)
3.5.3
machine bounding box, noun

bounding box (3.5.1) for which the surfaces are parallel to the machine coordinate system

(3.5.11)
3.5.4
master bounding box, noun
bounding box (3.5.1) which encloses all of the parts (3.9.1) in a single build
3.5.5
geometric centre, noun
centroid

location at the arithmetic middle of the bounding box (3.5.1)

Note 1 to entry: The geometric centre of the bounding box can lie outside the part (3.9.1) that is enclosed by the

bounding box.
3.5.6
orthogonal orientation notation, noun

description of the orientation of the bounding box (3.5.1) according to overall length in decreasing

magnitude, parallel to the axes of the machine coordinate system (3.5.11)

Note 1 to entry: Notation typically consists of a combination of X, Y and Z, each referring to the corresponding

axis as defined by the machine coordinate system.

Note 2 to entry: Orthogonal orientation notation requires that the bounding box be aligned with the machine

coordinate system. Machine coordinate system and different bounding boxes, including examples of orthogonal

[8]
orientation notation, are illustrated in ISO/ASTM 52921 .
3.5.7
initial build orientation, noun

orientation of the part as it is first placed in the build volume (3.3.4)

[8]
Note 1 to entry: Initial build orientation is illustrated in ISO/ASTM 52921 .
3.5.8
part reorientation, noun

rotation around the geometric centre (3.5.5) of the part’s bounding box (3.5.1) from the

...