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BS ISO/ASTM — Overview of Standard Terminology for Additive Manufacturing (Coordinate Systems and Test Methodologies)
BS ISO/ASTM 52921:2013 Standard Terminology for Additive Manufacturing — Coordinate Systems and Test Methodologies Overview
🖨️ BS ISO/ASTM is the BSI British Standard series adopting ISO/ASTM joint international standards, with UK participation through the BSI Additive Manufacturing Technical Committee AMT/8. This batch covers one single-file standard: BS ISO/ASTM 52921:2013, “Additive manufacturing — Standard terminology — Coordinate systems and test methodologies.” The standard defines standard terminology and conventions for coordinate systems and test methodologies in the additive manufacturing field, providing a unified basis for location, orientation, and testing language in additive manufacturing (3D printing), and is an important member of the ISO/ASTM 52900 series standard family.
💡 This standard is one of the additive manufacturing series standards jointly developed by ISO and ASTM International (the 52900 series), the first joint ISO/ASTM publication in additive manufacturing standardization; the UK version adopts ISO/ASTM 52921:2013.
1. Series Overview 📌
Additive manufacturing (AM), commonly known as 3D printing, is a process of joining materials layer by layer from three-dimensional model data to make objects. As AM technology moves from prototyping to serial production, the industry increasingly needs unified terminology, coordinate conventions, and test methodologies. ISO and ASTM International, through a joint working group, developed the 52900 series standards, of which ISO/ASTM 52921 specifically standardizes terminology related to coordinate systems and test methodologies.
This batch’s BS ISO/ASTM 52921:2013 was published in 2013, with ICS classification 25.040.20 (Numerically controlled machines) and 01.040.25 (Manufacturing engineering terminology), overseen by BSI TC AMT/8. The standard defines concepts such as location, orientation, coordinate axes, and test artifact in additive manufacturing, providing a unified reference framework for part design and production.
⚠️ This standard is a readable-text version. This article is based on the foreword, scope, and table of contents; specific term definitions and notes should be confirmed against the official BSI published edition.
2. Standard Structure and Technical Overview 📋
| Section/Topic | Content | Technical Focus |
|---|---|---|
| Scope | Defines the object | Standard terminology for coordinate systems and test methodologies in additive manufacturing |
| Terms and definitions | Basic concept definitions | Terms such as additive manufacturing, build platform, part location |
| Coordinate system conventions | Coordinate axis and direction definitions | X/Y/Z axis directions, build plane, layer direction conventions |
| Location and orientation | Part placement on build platform | Build direction, orientation angles (e.g., 0°/90°) |
| Test methodology requirements | Test artifact and test methods | Test artifact definition, test artifact types, test method hooks |
ISO/ASTM 52921, together with ISO/ASTM 52900 (general terminology), ISO/ASTM 52915 (data format specification), and others, forms the additive manufacturing standards system, of which 52921 is the basis for understanding subsequent test and design standards.
3. Key Technical Requirements 🔧
Based on the scope and structure of ISO/ASTM 52921, the key technical content focuses on the following:
- Terms and definitions: Systematically defines basic terms related to additive manufacturing coordinate systems and test methodologies, such as build platform, build direction, and layer, ensuring consistency of industry terminology.
- Coordinate system conventions: Specifies coordinate axis definitions for AM equipment, including the X, Y, and Z axis direction conventions and positive directions, and the relationships of each axis to the build plane and layer direction.
- Location and orientation: Specifies methods for representing part location and orientation on the build platform, including the effect of build direction on anisotropy of mechanical properties and the meaning of placement angles such as 0° and 90°.
- Test methodology requirements: Links the test artifact concept and terminology to subsequent test method standards (e.g., ISO/ASTM 52902 test artifacts), providing a unified basis for testing and characterization of AM parts.
✅ Coordinate conventions are critical in additive manufacturing: the mechanical properties, surface quality, and dimensional accuracy of AM parts are usually directional (anisotropic); unified coordinate axes and direction definitions provide a common language for part design, process planning, and test result comparison.
4. Representative Standard Technical Interpretation 🔍
BS ISO/ASTM 52921:2013 — Standard terminology for additive manufacturing: coordinate systems and test methodologies
Scope: Defines standard terminology and conventions for coordinate systems and test methodologies in additive manufacturing, providing a unified reference framework for AM part design and testing.
Key points: This standard clarifies the coordinate system shared by AM equipment and parts: typically based on the build platform, specifying X, Y, Z axis directions (e.g., Z axis along the build direction), and defining concepts such as the build plane and layer direction. The standard also specifies methods for representing part location and orientation on the build platform, providing the key design consideration of “the effect of build direction on anisotropic part properties.” By unifying terminology and coordinate systems, the standard enables comparison of part location and test results among different manufacturers and processes (e.g., powder bed fusion, material extrusion), and is an important member of the ISO/ASTM 52900 series family, serving as the reference basis for subsequent test artifact standards (52902) and design standards (52910).
5. Engineering Practice and Application 🛠️
In additive manufacturing engineering practice, BS ISO/ASTM 52921 is used at the following stages:
- Part design: Designers orient parts in the 3D model per the unified coordinate system and consider the effect of build direction on anisotropy of mechanical properties, optimising part placement on the build platform.
- Process planning: Process engineers generate build files per the standard’s coordinate axis conventions, standardising layer slicing and support structure generation.
- Testing and characterization: Test personnel perform part testing per the unified terminology and test artifact concepts, comparing test results across processes and batches.
- Industry communication: Suppliers and customers use unified additive manufacturing terminology to communicate part location, orientation, and test requirements, avoiding ambiguity.
⚠️ This is a terminology standard and does not itself give specific numerical requirements or test procedures; test method details are in test artifact standards such as ISO/ASTM 52902, and material and process requirements are in the relevant process specifications.
6. FAQ ❓
What is the relationship between ISO/ASTM 52921 and ISO/ASTM 52900?
ISO/ASTM 52900 is the general terminology standard for additive manufacturing, defining basic concepts such as process classification (powder bed fusion, material extrusion, etc.); ISO/ASTM 52921 specifically defines terminology and conventions related to coordinate systems and test methodologies, and is a dedicated terminology standard in the 52900 series family.
ISO/ASTM 52900 is the general terminology standard for additive manufacturing, defining basic concepts such as process classification (powder bed fusion, material extrusion, etc.); ISO/ASTM 52921 specifically defines terminology and conventions related to coordinate systems and test methodologies, and is a dedicated terminology standard in the 52900 series family.
Why does additive manufacturing need a unified coordinate system?
AM part performance is directional; unified coordinate axes and direction definitions (e.g., Z axis along the build direction) make results from different equipment, processes, and tests comparable, providing a common language for design, process planning, and quality evaluation.
AM part performance is directional; unified coordinate axes and direction definitions (e.g., Z axis along the build direction) make results from different equipment, processes, and tests comparable, providing a common language for design, process planning, and quality evaluation.
What is “build direction”?
Build direction is the direction of layer-by-layer accumulation of a part during additive manufacturing, typically corresponding to the axis perpendicular to the build plane (e.g., Z axis); it significantly affects mechanical properties, surface quality, and support requirements.
Build direction is the direction of layer-by-layer accumulation of a part during additive manufacturing, typically corresponding to the axis perpendicular to the build plane (e.g., Z axis); it significantly affects mechanical properties, surface quality, and support requirements.
Does this standard give test procedures and numerical requirements?
No. It defines terminology and conventions; test artifact types and test procedures are in standards such as ISO/ASTM 52902, and specific numerical requirements are in the relevant material and process specifications.
No. It defines terminology and conventions; test artifact types and test procedures are in standards such as ISO/ASTM 52902, and specific numerical requirements are in the relevant material and process specifications.
How can the official text be obtained?
Obtain the official published edition of BS ISO/ASTM 52921:2013 from BSI (BSI Standards Online / British Standards Online) and verify the latest editions of other standards in the 52900 series.
Obtain the official published edition of BS ISO/ASTM 52921:2013 from BSI (BSI Standards Online / British Standards Online) and verify the latest editions of other standards in the 52900 series.