Material Testing Machines


The ClassNK Testing Machine Department (TMD) has been registered as a Calibration Laboratory for force and hardness, in accordance with the traceability system under the Japan Calibration Service System (JCSS) of the Measurement Law of Japan. The Force Calibration Machines used by TMD to provide inspection and calibration services are fully traceable to the Japanese national force standard. TMD is also accredited by the National Institute of Technology and Evaluation (NITE) as a JCSS Accredited Calibration Laboratory covered by the International Mutual Recognition Arrangements (MRA) based on JIS Q 17025 (ISO/IEC 17025).

ClassNK provides inspection and calibration services within an approved calibration range at the request of interested members of industry. When the results of a calibration satisfy the requirements of the applicable standard, ClassNK issues a certificate of calibration with the international MRA logo mark on it. The certificate certifies both that the traceability of the accuracy of the calibrated measuring instrument to the national standard is assured and that the accuracy of the instrument or machine is accepted globally.

The Society is accredited under JCSS, which uses JIS Q 17025 (ISO/IEC 17025) as a standard for recognition, and is administered in accordance with the ISO/IEC 17011 accreditation scheme. The accrediting organization IAJapan, which operates JCSS, is a signatory to the MRA of the Asia Pacific Laboratory Accreditation Cooperation (APLAC) and the International Laboratory Accreditation Cooperation (ILAC). The ClassNK Testing Machine Department is a JCSS Accredited Calibration Laboratory covered by the International MRA. The accreditation number of the Testing Machine Department is 0093.

Table of Approved Calibration Ranges (as of 1 April 2016)

Category Field Type Range of Calibration Best
capability (k=2)
Force Force
Based on
method set
forth in
JIS B 7728
Compression From 30 N up to 1.5 kN 0.024 %
From 100 N up to 1.5 kN 0.024 %
From 100 N up to 5 kN 0.023 %
From 1 kN up to 50 kN 0.024 %
From 5 kN up to 500 kN 0.031 %
From 50 kN up to 5000 kN 0.020 %
Based on
method set
forth in
JIS B 7721
Compression From 1 N up to 1 MN 0.22 %
More than 1 MN up to 10 MN 0.35 %
Tension From 1 N up to 100 KN 0.26 %
More thanFrom 100 KM up to 1 MN 0.44 %
Hardness Rockwell
Machine etc.
From 20 HRC up to 25 HRC 0.54 HRC
More than 25 HRC less than 35 HRC 0.58 HRC
From 35 HRC up to 45 HRC 0.48 HRC
More than 45 HRC less than 55 HRC 0.56 HRC
From 55 HRC up to 65 HRC 0.51 HRC