Construction Fixings

Here Stefan Baus of GEDORE and Rainer Janecke of STAHLWILLE Germany, members of the Working Group ISO/TC 29/SC 10/WG 3, discuss how a revision of the current version of ISO 6789 will help make clear whether the calibration of torque wrenches can be simplified without compromising the quality of the result.

There is a lack of acceptance in the market for the current edition of ISO 6789:2017, which has led to calls for an editorial and regular revision (every five years), as well as a revision of the content. The international Working Group ISO/TC 29/SC 10/WG 3 is tackling this major challenge.

Several goals are being pursued with the new version of ISO 6789. One goal is to provide more transparency about the addressees of both parts: ISO 6789-1 is aimed at manufacturers only and ISO 6789-2 is aimed at calibration laboratories accredited based on ISO/IEC 17025 and calibration services. They want to record all detectable influences in the application of a hand-operated torque tool with the respective individual measurement uncertainty (MU) and to output them as a total MU. ISO 6789-2 will make sure that these procedures and their results are comparable all over the world.

In addition, we aim to reduce the complexity of ISO 6789-2 without compromising on quality and informative value. For instance, hand operated screwdriving tools previously used on the market but not included in ISO 6789 are to be newly included, such as the ‘Slipper’.

Until the current edition of ISO 6789, the calibration of an angle function integrated in torque wrenches was not considered in ISO 6789. The ISO/TC 29/SC 10/WG 3 Working Group wants to meet this requirement with the new edition.

Also new is the approach of describing a valid process for a test between the intervals of an annual calibration or MCT (machine capability test) in order to optimise a company’s internal processes. All in all, a hard and extensive piece of work. However, it is good to know that a dedicated team of experts from many countries is taking on this task.  

New CFE Working Group on pre-installed fasteners

The European association Construction Fixings Europe (CFE) has enlarged its scope with a new Working Group on pre-installed fasteners in concrete, such as anchor channels and reinforcement products.

The new Working Group consists of three new CFE member companies, Max Frank, Leviat Limited and PohlCon GmbH, as well as the established CFE members fischer and Hilti. During the kick-off workshop of the new Group on 5^th June, several fields of activity were decided, including networking with other stakeholders; publication of technical guidelines for designers and end users; maintenance of European Assessment Documents and Eurocodes; and activities to ensure a level playing field. Thomas Holland-Letz, technical director at CFE, welcomed the decision of this Group to join CFE and emphasised the synergies between the existing Working Group for post-installed anchors and this new Group with respect to the implementation of the new CPR, sustainability and digitalisation. 

After the kick-off workshop, the Group joined the CFE Spring Meeting to discuss the implications of the new EU Construction Products Regulation (CPR) for the holders of European Technical Assessments (ETAs).