Author John Newnham is a fastener specialist at the British Forging Consortium, which makes forward-looking forecasts for fastener manufacturers and distributors. Here, he believes that fastener companies need to pay attention to the implications of the upcoming revision of ISO 898-1, and give the following insights.
ISO 898-1 is a very important mechanical performance standard for carbon steel and alloy steel bolts. It specifies the strength class, the type of material allowed, and the test requirements and methods. This standard is not only used to define the performance of ISO standard bolts, screws and studs, but is also used in many non-standard drawings. The latest version of the standard was published in 2009, but a number of changes to the version of the content have now been agreed, and a complete new standard may be available soon.
The 2009 edition of the standard is quite controversial, and everyone has raised negative opinions on several aspects of the standard. Therefore, the 11th Subcommittee of ISO Technical Committee 2 drafted and revised this document for the problems found, and the amendments made it possible to re-publish ISO 898-1.
The revised draft includes a number of technical amendments, as well as a number of textual changes to clarify concepts, as well as necessary updates to common reference to relevant standards. The newly agreed ISO will adopt the reference standard without dated, so any reference standard applies to its latest version.
The draft also includes a number of technical changes to the definition and determination of carbon and decarbonization, including the newly defined surface conditions, decarburization of ferrite, and clarification of non-carburizing for grades 8.8 and above. Concept, while previously defined tests are not available for low intensity levels. At the same time, the microhardness method and the metallographic method for determining these states 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 also improved. As the new version will adopt the new ISO insights in the updated standard, these modifications will result in products that are currently in stock no longer meeting the new requirements and will no longer be accepted in at least one country.
Post-translation instructions: On September 15, 2011, the ISO website published the news of ISO 898-1:2009 to be revised, and issued a discussion draft of ISO/DIS 898-1, the draft. In accordance with established practice, the letter of the vote ended on March 15, 2012. If there is no accident, it is estimated that a new version will be issued around June. The news disclosed in the above magazine shows two important changes to the standard: distinguishing between the low-strength grade carburized layer and the high-strength grade carbon-increasing layer, and the means to improve the identification. It seems that the new ISO 898-1 will be available in 2012, and we welcome it.
Translator: Jin Weifeng fastener network consultant expert Wang Weiwu
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