Content with FAQ

18 December 2015
DOP in its the full name means Declaration of Performance. It is a document that the manufacturer of the product should supply forevery CE (UKCA) approved product in line with the requirements of the Construction Products Regulation (CPR) or equivalent in the United Kingdom. The DOP contains information about the manufacturer, the construction product/s to be CE (UKCA) Marked ; the product intended use/s and the declared essential performance characteristics of the product.
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18 December 2015
J2 and JR refer to the material’s sub-grade - its fracture toughness - which is measured in joules [J] of a material’s toughness at a particular temperature. J2 is a material with a minimum of 27 joules at -20C while JR is a material with a minimum of 27 Joules at +20C (room temperature). A JR material is normally used in an internal environment whereas a J2 is for external use.
Read more about What is the difference between J2 and JR? Can they be used as substitutes for each other?

18 December 2015
For high-strength structural bolting assemblies for preloading to BS EN 14399 an overall recommendation is to have a minimum of 1 (one) thread above the unloaded face of the nut, and a minimum of 4 (four) threads before the shank of the bolt and the nut.
Read more about Are two threads protruding through high-strength structural bolting assemblies for preloading enough?

18 December 2015
Due to safety reasons and according to BS 4604-1 (Withdrawn): “If after final tightening a bolt or nut is slackened off for any reason, the bolt, nut and washer shall be discarded and not re-used.” Under the latest BS EN 14399 standard: If the assembly has been tightened to the minimum force of 70%, the assembly cannot be re-used. Andrews Fasteners recommend, once assembly has been preloaded, in any form and needs to be de-assembled, to discard it and replace it with fresh assembly (and relevant components like DTI washers) due to wearing off applied lubrication which may invalidate torque figures supplied for installation (k-Class K1 or K2) or cause difficulty to compress DTI washers at the right level (k-Class K0).
Read more about Can high-strength structural bolting assemblies for preloading (HSFG) be de-assembled once they have been assembled?

18 December 2015
A single lap joint is a joint with two plates are connected with a single row of bolts. In the case of clause 3.6.1(10) which concerns a single lap joint with a single row of bolts, the bolts require two washers because as the plates are pulled apart the connection bends and the head/nut tries to pull through the plate.
Read more about What is a single lap joint according to EN 1993-1-8:2005, 3.6.1.?

18 December 2015
To accommodate the thickness of zinc it is normal practice to over-tap the nut thread. This operation reduces the strength of the nut and the overall strength of the nut and bolt assembly. To improve the strength of the assembly manufacturers use either a thicker nut (increasing the number of threads between the nut and the bolt in the assembly) or a higher-grade nut. BS EN 15048-1: To achieve full tensile resistance, hot-dip galvanized assemblies can require special measures, see EN ISO 10684, Annex F.
Read more about Should higher-grade nuts be specified for use with galvanized or sherardized set screws and bolts on CE (UKCA) approved assemblies?

18 December 2015
There is no generally accepted definition for secondary steelwork. In the first interpretation the definitions given in clause 3.7 of BS EN 10225 may be used as a reference: Clause 3.7 Secondary elements elements of minor importance, failure of which would be unlikely to affect the overall integrity of the installation. More you can read more on BCSA memorandum No 158-12 .
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18 December 2015
Steel is arguably the most sustainable of the major structural materials. It has numerous sustainability benefits, which are guaranteed to be realised whenever steel is used. They include low waste, flexibility, offsite manufacture, speed, resource efficiency, adaptability, demonstrability, long-lasting appeal, safety, reusability and recyclability. These inherent characteristics result in many social, environmental and economic benefits to satisfy sustainability’s “triple bottom line”. More information about the sustainability of the steel you can be read in BCSA memorandum No 243/12 .
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18 December 2015
Unlike most other construction materials steel can be recycled indefinitely without loss of property or performance. This is referred to as multi-cycling. It means steel always has a value, which guarantees that virtually none is ever disposed of in a landfill. The multi-cycling of steel is a self-sustaining system that predates modern appreciation of environmental issues and would continue in the unlikely event that they should ever lessen in importance.
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18 December 2015
HR should stand for High Resistance and HV for Hochfeste Bolzen mit Vorspannung (in English high resistance bolts for pretension). The second is an official description, and they should serve the same purpose. See also: What is the difference between HR and HV bolt assemblies?
Read more about What does the HR & HV symbols mean?