BS 7371-8:2011
Coatings on metal fasteners Specification for sherardized coatings
| Standard number: | BS 7371-8:2011 |
| Pages: | 20 |
| Released: | 2011-03-31 |
| ISBN: | 978 0 580 71610 2 |
| Status: | Standard |
BS 7371-8:2011
This standard BS 7371-8:2011 Coatings on metal fasteners is classified in these ICS categories:
- 21.060.01 Fasteners in general
- 25.220.40 Metallic coatings
This part of BS 7371 specifies requirements for sherardized coatings on iron and steel fasteners and accessories applied by thermal diffusion of zinc powder onto a component’s surface.
NOTE Hydrogen embrittlement is not induced as a result of this coating process.
The coating consists of zinc/iron alloys, which are subsequently treated using either a zinc phosphate treatment (see BS 7371-9:1996, Type 2) or a suitable substitute treatment similar to those used in electroplating zinc (see BS 7371-3:2009) and mechanical plating (see BS 7371-7:2010). This results in a dust free surface, which, when required, can be lubricated to give controlled torque/clamping force properties (see BS 7371-2:1993).
In addition to the requirements in this part of BS 7371, the requirements in BS 7371-1:2009 that are applicable to sherardized coatings apply.
This part of BS 7371 also specifies requirements for:
the local coating thickness for six grades of coating;
possible types of post treatment;
the assessment of corrosion resistance of unused coated parts when subjected to neutral salt spray testing (see BS EN ISO 9227:2006).