In 2016, the PLX family (duplex stainless steel) was presented since the main concern was to offer a solution to the cases of SCC fracture that occurred; resistance to SCC is a characteristic of the structure of duplex steels. Drafts of the UIAA anchor standard published at the time supported the decision, tabulating 5 degrees of corrosion resistance and placing the duplex at grade 2 between titanium (grade 1) and 316 (grade 3).
In the latest publication of the EN959 anchor standard, the table of anchor features and according to the “type of material and installation environment” was introduced as a novelty compared to previous versions and it simplified the tables that had inspired it (drafts and studies UIAA), offering three anchor types depending on the material used and three corresponding groups of installation environments. In order to simplify the choice for the installer and in order to work with the maximum of best praxis, the results were:
– Grade 1: for environments with aggressive SCC. Using Grade 2 titanium as an example.
– Grade 2: for outdoor environments generally. With Inox 316 as an example.
– Grade 3: for indoor locations without corrosive potentials. With galvanized steel as an example.
Given that the duplex then went through and according to the standard, to share main features with the Inox 316L, and in addition the fact that duplex presented additional difficulties such as: lack of knowledge according to the type of material by above all non-technical public; Difficulty finding other components (like for example: Allen screws) of the same material to avoid galvanic corrosion and with a greater difficulty in forming and welding, it was decided to launch a new family with Inox 316L.