Structure and Numbering Rules of JIS Standard Numbers

Japanese Industrial Standards (JIS) standard numbers have a systematic structure designed to efficiently identify the field and content of each standard.

Basic Structure

JIS standard numbers consist of three main elements:

The first element is a single alphabetic character representing the division, which indicates the technical field to which the standard belongs. The second element is a four-digit or five-digit number representing the classification and serial number. The third element is a four-digit number indicating the year of publication, written after a colon.

For example, in the standard number “JIS Z 8301:2008,” “Z” indicates the division (Miscellaneous), “8301” represents the classification number, and “2008” indicates the year of publication.

Division Symbol System

Division symbols are systematically assigned according to industrial sectors. The major division symbols and their corresponding fields are as follows:

Table 1: JIS Division Symbols and Corresponding Fields

Division Symbol	Field	Coverage
A	Civil Engineering and Architecture	General construction sector
B	General Machinery	Machine elements, machine tools, etc.
C	Electronics and Electrical Machinery	Electrical and electronic equipment
D	Automobiles	Automotive industry
E	Railways	Railway systems
F	Ships	Shipbuilding industry
G	Iron and Steel	Ferrous metals
H	Nonferrous Metals	Non-ferrous metals and alloys
K	Chemicals	Chemical products and chemical analysis
L	Textiles	Textile industry
M	Mining	Mining industry
P	Pulp and Paper	Pulp and paper industry
Q	Management Systems	Quality management, environmental management, and other management systems
R	Ceramics	Ceramic industry
S	Daily and Miscellaneous Goods	Consumer-related products
T	Medical Safety Equipment	Medical devices and safety equipment
W	Aviation	Aviation industry
X	Information Processing	Information technology
Z	Miscellaneous	Standards not classified in other divisions

Structure of Numerical Portion

The numerical portion adopts a hierarchical classification system.

The first digit represents the major classification within the division, while the second digit functions as a medium classification representing the field. Further subdivision using the second digit is also possible when necessary.

Standard numbers are assigned using a sequential numbering method for each classification. Numbering begins from 01 for two-digit cases and from 0 for subdivided one-digit cases. This method ensures systematic management of standards and provides future expandability.

Operation of Part System

For standards composed of multiple parts, systematization is achieved using part numbers. For example, as shown in “JIS C 61326-1:2017,” the part number is displayed after a hyphen. This method enables systematic management of a series of related standards.

Special Considerations in Numbering

When assigning standard numbers, numbers may be skipped as necessary to avoid duplication with existing numbers. Additionally, there may be gaps in numbering that occurred during the transition process from the three-digit or fewer numbering system to the four-digit system.

To ensure consistency with international standards, when corresponding international standards exist, a policy has been adopted to align JIS standard numbers with international standard numbers as much as possible. This clarifies the correspondence between international standards and JIS standards, improving convenience for users of the standards.

Handling of Standard Numbers During Revision

When standards are revised, as a general rule, the standard number is maintained and only the publication year is updated. However, when the content of a standard undergoes major revision or when the standard is restructured, a new standard number may be assigned.

Such flexible operation enables the development of a standard system that maintains continuity of standards while responding to technological progress and changes in societal needs.

Alignment with International Standards

With the advancement of globalization in the world economy and the increase in international trade of goods and services, the importance of international standards such as ISO and IEC has grown. By harmonizing international standards with national standards of each country, products and technologies can be used across national borders, and this is expected to contribute to the facilitation of international trade.

For JIS as well, harmonization with international standards has been promoted following the entry into force of the WTO (World Trade Organization) TBT Agreement (Agreement on Technical Barriers to Trade) in 1995. Furthermore, with the legal amendment of July 1, 2019 (Reiwa 1), the promotion of international standardization was added to the legal purposes.

Currently, when JIS standards correspond to or align with international standards, and when international standards have five-digit numbers, JIS adopts five-digit numbers to match them. For example, JIS Q 17000 “Conformity assessment—Vocabulary and general principles,” which is a translation of ISO/IEC 17000, follows this practice. Additionally, in the “Electronics and Electrical Machinery” division, the standard numbers of some standards have been changed to five-digit numbers corresponding to IEC standards.

Review Cycle and Currency of Standards

Standards established or revised are reviewed within at least five years from the date of establishment or revision. Through this review, the competent minister confirms (continues as is), revises, or abolishes the JIS. This regular review process ensures that standards remain current with technological advances and changes in market conditions.

When JIS establishment or revision is performed, the name, number, and the type and date of establishment or revision are published in the official gazette. The content is made publicly available as standard specifications on the website of the Japan Industrial Standards Committee (JISC).

Systems to Promote JIS Establishment

To promote the establishment of JIS standards, several systems have been introduced. These include the Technical Specification (TS) system, the Technical Report (TR) system, and the newly added Preliminary Draft for JIS (PD) system in August 2023 (Reiwa 5).

The PD system aims to publish information that forms the basis of JIS drafts (such as simplified translations of international standards) as “Preliminary Drafts for JIS (PD)” prior to creating JIS drafts when converting international standards to JIS. This system collects a wide range of opinions from stakeholders, promotes open discussion, facilitates consensus building, and contributes to the prompt creation of JIS drafts.

Conclusion

The JIS numbering system represents a well-organized framework that balances systematic classification with flexibility for future development. By understanding this structure, users can efficiently navigate the vast landscape of Japanese industrial standards. The ongoing alignment with international standards, regular review processes, and new mechanisms for standard development ensure that JIS remains relevant and effective in meeting the evolving needs of industry and society. For professionals working in regulated industries or those requiring compliance with Japanese standards, familiarity with this numbering system is essential for proper standard identification, application, and communication.