New standards in metrology

Standards and guidelines are significant success factors for the competitiveness of a company. Learn more about new standards and guidelines for roughness measurement and cutting edge evaluation that are currently in development.

New ISO standards for profile and area-based surface roughness measurement

Standardization body: Technical committee 213 Dimensional and geometrical product specifications and verification 

Standardization in the field of geometrical product specifications (GPS), i.e. macro- and microgeometry specifications covering dimensional and geometrical tolerancing, surface properties and the related verification principles, measuring equipment and calibration requirements including the uncertainty of dimensional and geometrical measurement. The standardization includes the basic layout and explanation of drawing indications (symbols).

Profile-based roughness measurement

Current standards for measuring profile roughness include ISO 4287 and ISO 4288. A new standard is aimed at combining and extending existing guidelines and solving existing problems for the user. ISO 21920 for this purpose deals with the surface properties in the technical product documentation and includes the following:

  • ISO/NP 21920-1
    Geometrical product specifications (GPS) -- Surface texture: Profile -- Part 1: Indication of surface texture
  • ISO/NP 21920-2
    Geometrical product specifications (GPS) -- Surface texture: Profile -- Part 2: Terms, definitions and surface texture parameters

Area-based roughness measurement

A new draft of ISO 25178 is currently being developed for area-based roughness measurements. This standard specifies terms, definitions and parameters for determining the surface texture using area-based measurement methods. Most parts of the new standard have already been completed, so that at present only the final touches are being made. Thus, among other things, the documents that determine the calibration of optical, area-based measuring instruments are currently being processed.

ISO/NP 25178 includes among others

  • ISO 25178-1:2016
    Geometrical product specifications (GPS) -- Surface texture: Area -- Part 1: Indication of surface texture
  • ISO 25178-2:2012
    Geometrical product specifications (GPS) -- Surface texture: Area -- Part 2: Terms, definition and surface texture parameters
  • ISO 25178-3:2012
    Geometrical product specifications (GPS) -- Surface texture: Area -- Part 3: Specification operators
  • ISO 25178-6:2010
    Geometrical product specifications (GPS) -- Surface texture: Area -- Part 6: Classification of methods for measuring surface texture

New VDI guidelines for evaluation and characterization of cutting edges

Fachbereich 3 Fertigungsmesstechnik (Division 3 Manufacturing Metrology)

Planned guidelines (in development):

  • VDI 2654-1 definition of parameters (please see illustration below)
  • VDI 2654-2
  • VDI 2654-3
  • VDI 2654-4 

The defined edge geometry of cutting tools is a crucial factor for the improvement of tool life and processing quality. In order to enhance the standardization of cutting edge measurement, Alicona is currently developing new standards with the Association of German Engineers (VDI) and partners in industry and research. Consequently, these standards are going to result in a global new EN ISO standard for cutting edge measurement.

There are numerous fields of application for the use of cutting edges in the manufacturing technology. However, a comparable measurement of edges and edge parameters has not been assured yet. As one of the international leading producers of optical 3D metrology, Alicona has sensed the need for standardization of cutting-edge measurement. Thus, Alicona contacted the Association of German Engineers (VDI), the National Metrology Institute PTB and leading research institutions.

Alicona's proposal to develop new guidelines for quality assurance and thus improving reproducibility, comparability and traceability of measuring results, was well received by industry and research. The focus of the joint venture is the creation of new standards for the measurement and evaluation of cutting edges and radii. The aim is to unify the description of cutting tools as well as the methods for measuring cutting edges. Establishing these guidelines shall determine the different functional requirements for edges and radii considering the needs of the industry.

The new standards for cutting edges are intended to help users in the interpretation of their measurements. Furthermore, it is thought to enhance reproducibility of measurement results as well as the comparability of measurements and measurement devices of different manufacturers. Consequently, these standards are going to result in a global new EN ISO standard for cutting edge measurement.

VDI 2654-1

Definition of parameters:

•Wedge angle β

•Profile flattening Sβ
Min Distance from cutting edge to apex

•Symmetry angle φ

•Projected clearance roundness Sα

•Projected rake roundness Sγ 

•Symmetry parameter of cutting edge KS

•Area symmetry parameter of cutting edge Area aspect ratio KA

•Ellipse aspect ratio  KEA

•Tilt angle ψE

•Radius of cutting edge rβ

•Clearance side bevel length S′α

•Angle of clearance side bevel αb

•Rake side bevel length S′γ 

•Angle of rake side bevel γ b

Do you have any questions?

Would you like to receive a full list of standards and guidelines, that measuring devices by Alicona correspond with? Do you want more information on the standardization work of Alicona? For this or any other inquiry, please feel free to contact us at metrology(at)