ISO/TC 2/SC 14 - Surface coatings

The objective of this document is to conduct a neutral salt spray test in accordance with ISO 9227. The test is a proven method for assessing the corrosion protection of coatings of components such as bolts. For this reason, two coating variants were chosen for conducting the tests on hexagon bolts with a size of M6 × 50. The bolts were examined at specified points in time and the time of occurrence of grey veil, white rust and red rust was documented. The corrosivity of the salt spray was determined by means of two methods and also documented in an evaluation form. These two methods are the assessment of the mass loss of an uncoated steel panel as specified in ISO 9227 as well as the determination of the time until appearance of red rust on hot-dip galvanized steel panels in accordance with ISO 4042 and ISO 10683. The processing steps are specified in detail in a manual that was provided to the test participants. If followed precisely, these instructions allow for a comparative analysis of the results from the individual labs and make it possible to determine the reproducibility of the salt spray test. Another objective is to compare the two methods used to determine the corrosivity of the salt spray in order to establish the suitability of these methods by comparing the corrosion assessment results obtained for the bolts. In addition, the normative operating parameters (temperature in the test cabinet, collection rate, pH and density or NaCl concentration of the solution collected) were documented for every inspection date in order to ascertain whether there is any correlation with the results of the corrosion assessment performed on the bolts.

This document specifies requirements for steel fasteners with electroplated coatings and coating systems. The requirements related to dimensional properties also apply to fasteners made of copper or copper alloys. It also specifies requirements and gives recommendations to minimize the risk of hydrogen embrittlement, see 4.4 and Annex B. It mainly applies to fasteners with zinc and zinc alloy coating systems (zinc, zinc-nickel, zinc-iron) and cadmium, primarily intended for corrosion protection and other functional properties: — with or without conversion coating, — with or without sealant, — with or without top coat, — with or without lubricant (integral lubricant and/or subsequently added lubricant). Specifications for other electroplated coatings and coating systems (tin, tin-zinc, copper-tin, copper-silver, copper, silver, copper-zinc, nickel, nickel-chromium, copper-nickel, copper-nickel-chromium) are included in this document only for dimensional requirements related to fasteners with ISO metric threads. The requirements of this document for electroplated fasteners take precedence over other documents dealing with electroplating. This document applies to steel bolts, screws, studs and nuts with ISO metric thread, to other threaded fasteners and to non-threaded fasteners such as washers, pins, clips and rivets. NOTE Electroplating is also applied to stainless steel fasteners, e.g. for the purpose of lubrication in order to avoid galling. Information for design and assembly of coated fasteners is given in Annex A. This document does not specify requirements for properties such as weldability or paintability.

This document presents the latest knowledge related to hydrogen embrittlement, translated into know-how in a manner that is complete yet simple, and directly applicable to steel fasteners.

This document specifies requirements for non-electrolytically applied zinc flake coating systems for steel fasteners. It is applicable to coatings: — with or without hexavalent chromium; — with or without top coat; — with or without lubricant (integral lubricant and/or subsequently added lubricant). It is applicable to bolts, screws, studs and nuts with ISO metric thread, to fasteners with non-ISO metric thread, and to non-threaded fasteners such as washers, pins, clips, etc. This document does not specify requirements for such fastener properties as weldability or paintability. It is not applicable to mechanically applied zinc coatings. NOTE Coatings in accordance with this document are especially used for high strength fasteners (≥ 1 000 MPa) to avoid risk of internal hydrogen embrittlement (IHE — see 4.4). Information for design and assembly of coated fasteners is given in Annex A.

ISO 1891-2:2014 specifies terms and definitions for fastener coatings, primarily intended for corrosion protection and functional purposes. These terms are mainly intended for use in conjunction with ISO 4042, ISO 10683 and ISO 10684.

ISO 10684:2004 specifies material, process, dimensional and some performance requirements for hot dip spun galvanized coatings applied to coarse threaded steel fasteners from M8 up to and including M64 and for property classes up to and including 10.9 for bolts, screws and studs and 12 for nuts. It is not recommended to hot dip galvanize threaded fasteners in diameters smaller than M8 and/or with pitches below 1,25 mm. ISO 10684:2004 primarily concerns the spun hot dip galvanizing of threaded steel fasteners, but it may also be applied to other threaded steel parts. The specifications given in this document may also be applied to non-threaded steel parts such as washers.

ISO 1891-2:2014 specifies terms and definitions for fastener coatings, primarily intended for corrosion protection and functional purposes. These terms are mainly intended for use in conjunction with ISO 4042, ISO 10683 and ISO 10684.

This document deals with electroplating process evaluation for fasteners, including fastener expected coating properties. This document is a complement to CQI-11 in order to deal with fastener specific aspects not fully covered by CQI-11, and to clarify some questions/items when they are not fully suitable for fasteners. This document is a guide applicable to all parties involved in the supply chain for coated fasteners, i.e. fastener manufacturers, chemical suppliers, electroplaters and purchasers. The requirements for electroplating fasteners specified in this document are essentially based on ISO 4042, ISO/TR 20491 and ISO 16047. NOTE Requirements for electroplating fasteners are also given in ASTM F1941/F1941M.

This document specifies requirements for electroplated coatings and coating systems on steel fasteners. The requirements related to dimensional properties also apply to fasteners made of copper or copper alloys. It also specifies requirements and gives recommendations to minimize the risk of hydrogen embrittlement; see 4.4 and Annex B. It mainly applies to zinc and zinc alloy coating systems (zinc, zinc-nickel, zinc-iron) and cadmium, primarily intended for corrosion protection and other functional properties: — with or without conversion coating; — with or without sealant; — with or without top coat; — with or without lubricant (integral lubricant and/or subsequently added lubricant). Specifications for other electroplated coatings and coating systems (tin, tin-zinc, copper-tin, copper-silver, copper, silver, copper-zinc, nickel, nickel-chromium, copper-nickel, copper-nickel-chromium) are included in this document only for dimensional requirements related to fasteners with ISO metric threads. This document applies to bolts, screws, studs and nuts with ISO metric thread, to fasteners with non-ISO metric thread, and to non-threaded fasteners such as washers, pins, clips and rivets. Information for design and assembly of coated fasteners is given in Annex A. This document does not specify requirements for properties such as weldability or paintability. NOTE Other International Standards specify differing electroplating processes. For electroplating of fasteners, the requirements of this document apply, unless otherwise agreed.

ISO 10683:2014 specifies requirements for non-electrolytically applied zinc flake coatings for steel fasteners. It applies to coatings: with or without hexavalent chromium; with or without top coat; with or without lubricant (integral lubricant and/or subsequently added lubricant). It applies to bolts, screws, studs and nuts with ISO metric thread, to fasteners with non-ISO metric thread, and to non-threaded fasteners such as washers, pins, clips, etc. ISO 10683:2014 does not specify requirements for such fastener properties as weldability or paintability. It does not apply to mechanically applied zinc coatings.