ISO 3506-1-2020 pdf download

ISO 3506-1-2020 pdf download.Fasteners一Mechanical properties of corrosion-resistant stainless steel fasteners – Part 1: Bolts, screws and studs with specified grades and property classes. 6.3 Finish Unless otherwise specified, fasteners in accordance with this document shall be supplied clean and bright. For maximum corrosion resistance, passivation Is recommended. Fasteners that are passivated in accordance with ISO 16048 may additionally be referenced on the label with the letter “Ps immediately after the property class symbol (see 1th4). NOTE 1 Passlvated fasteners do not always show a bright surface finish. Bolts, screws and studs are often used in bolted joints where the preload is achieved by torque tightening. Therefore, lubrication of stainless steel fasteners is recommended in order to avoid galling during tightening. NOTE 2 Several parameters can increase the risk of galling for stainless steel fasteners In bolted assemblies during tightening such as thread damage, high preload, high tightening speed. NOTE 3 For the time being, requirements concerning surface discontinuities and torque/clamp force properties are not specified in International Standards for stainless steel fasteners. A controlled torque/clamp force relationship can be obtained for stainless steel fasteners by means of an adequate finish, either just with a lubricant or with a coating, top coat and/or sealer including lubricant. In this case, the designation and/or labelling should include the letters “Lu immediately after the symbol of the property class, e.g. A4-8OLu. In conjunction, appropriate measures and means of tightening should be selected in order to achieve the required preload. When specific requirements are necessary, it shall be agreed between the supplier and the purchaser at the time of the order. 6.4 Corrosion resistance For corrosion resistance purpose, bolts, screws and studs should be mated with nuts and washers of the same stainless steel grade (e.g. nuts A2 with bolts A2, etc.). Other combinations are possible (e.g. nuts A4 with bolts D4), providing that: — the component with the lowest corrosion resistance shall always be taken into account, — the risk of galling should be considered, and — it is strongly recommended that an experienced fastener metallurgist be consulted. When using stainless steel fasteners with non-stainless steel parts in bolted joints, e.g. galvanized steels, it is advised that the use of isolation components be considered in order to avoid galvanic corrosion. 7 Mechanical and physical properties When tested by the methods specified in Clause.9, the bolts, screws and studs of the specified stainless steel grade...