Bolt mechanical performance standard ISO898-1 revision is coming soon

Author John. Newborn (John Newnham) is a fastener specialist for the British Forging Federation and specializes in making forward-looking predictions for fastener manufacturers and distributors. Here, he believes that fastener companies need to pay attention to the implication of the upcoming ISO 898-1 revision and give the following insights.

ISO 898-1 is a very important mechanical property standard for carbon steel and alloy steel bolts. It specifies strength levels, types of materials allowed, and test requirements and methods. This standard is not only used to define the performance of ISO standard bolts, screws and studs, but also used in many non-standard drawings. The latest version of the standard was published in 2009, but changes to a considerable amount of the content of this version have now been agreed upon, and a complete new standard may soon be introduced.

The 2009 version of the standard is quite controversial. Everyone has put forward negative opinions on several aspects of the standard. Therefore, the 11th Committee of the ISO Technical Committee No. 11 drafted and amended this document in response to the problems found, and the revisions caused it to propose the re-issuance of ISO 898-1.

The revised draft includes some technical amendments, as well as a number of textual changes to clarify the concept. It also includes the necessary updates to common reference standards. The newly agreed ISO will adopt the reference standard's non-marked approach, so any reference standard applies to its latest version.

The draft also carries out a series of technical changes to the definition and determination of carbon addition and decarburization, including the newly defined surface conditions, decarburization of ferritic structures, and clarification of non-carburizing applicable to strength grades of 8.8 and above. Concepts, while previously defined tests cannot be used for low intensity levels. At the same time, the microhardness method and the metallographic method for measuring these conditions have also been slightly modified.

In addition, it is also worth noting that the maximum and minimum values ​​of Brinell hardness of grades 8.8 and above are raised. Since the new version will adopt the new ISO view in the update standard, these modifications will result in the current inventory of products no longer meet the new requirements and will no longer be accepted in at least one country.

Post-translation note: On September 15, 2011, the ISO website posted news about the changes to ISO 898-1:2009, and issued a discussion draft of ISO/DIS898-1, that is, the draft. According to the usual practice, the letter vote ended on March 15, 2012. If there is no accident, it is estimated that the new edition will be issued around June. The news disclosed in the above magazine shows two important changes to the standard: the distinction between the low-strength carburized layer and the high-strength grade carbon-removal layer, as well as the means to improve the identification. It seems that the new ISO 898-1 will be available in 2012 and we welcome it.