This Standard specifies requirements and procedures for the chemical conversion treatment of metals usually prior to the application of a suitable organic protective coating and includes the following processes: (a) Phosphate conversion coatings for ferrous and non-ferrous metals. (b) Chromate conversion coatings for aluminium, magnesium, zinc and their alloys. Requirements on information to be supplied by the purchaser at the time of enquiry or order are contained in Appendix A. This Standard does not include requirements for conversion coatings applied to electroplated work (see AS 1789). Chromium free coatings are outside the scope of this Standard. Refer to supplier.