Bolt mechanical performance standards: ISO 898-1 will have more corrections
  Dr John Newnham is a fastener specialist for the British Forging Consortium (CBM), which makes forward-looking forecasts for fastener manufacturers and distributors. He believes that fastener companies need to pay more attention to the upcoming revision of ISO 898-1 and offer 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 that is acceptable, 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 proprietary drawings. The latest version of the standard was published in 2009, but at present there is quite a bit of content that has been modified, and a complete new standard may be available soon.
The 2009 edition of the standard is quite controversial, and we have negative comments 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 due to too many modifications, it proposed to republish 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 determined ISO will adopt the practice of not marking the reference standard date, so any reference standard applies to its latest version. The draft also includes a series of technical modifications to the definition and determination of carbonation and decarbonization, including newly defined surface conditions, ferritic decarburization, and clarification of non-carburizing concepts applicable to strength classes of 8.8 and above. The previously defined test cannot be used for low intensity levels. At the same time, the microhardness method and the metal structure method for measuring these states have also been slightly modified.
In addition, the increase in the maximum and minimum Brinell hardness of the performance class of 8.8 and above is also very concerned. As the new version will adopt the new ISO principles 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.
More information about CBM can be found on its website: http://
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