Content with HDG

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
You may notice, some products after hot-dip galvanization (HDG) coating, even in the same facility, using the same process, may look different from others. It can be noticed that some of the products will be much brighter and others much darker. There is nothing wrong with the product nor with the coating and any difference will depend on the product steel. Variations in coating thickness and the content of silicon in steel may cause different appearances on the finished product.
Read more about Why does galvanizing coating look different?

18 December 2015
A typical calculating lifetime of Hot-Dip Galvanising coating is set to 20 years on average, but this is based on many variables like humidity, temperature, environmental impact etc. If you require to calculate the coating lifetime for your localization, please ask a question to Galvanising Association or visit their website for more details. For more details please refer to: Finishes (Plating) Galvanizing is durable Corrosion Rates in UK & Ireland - Corrosion Map
Read more about What is the lifetime of galvanising coating?

25 August 2015
Self Colour / Black Finish Finish Specification S/C Self Colour Bare / Blackened (Black Oxide) Lightly Oiled products are supplied in a black finish with a light covering of oil Hot Dip Galvanised (HDG) Finish Specification HDG Hot Dip Galvanised EN ISO 10684 EN 1461 BS 7371-6 heavy coating deposits of molten zinc (40-180 microns) suitable for long term corrosion protection; a thicker coating deposit gives a longer life expectancy; it is most suitable for structural steelwork; the coating will affect the thread fit and assembly of fasteners due to the non-uniformity of the coating and the average coating thickness of 50-80 microns; in general the fullnuts are tapped oversize after the plating to allow for this but in some cases the bolt threads are undersize prior to coating; high temperature may affect the metallurgical properties of high tensile metals, i.
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