【国外标准】 Standard Specification for Phosphate/Oil Corrosion Protective Coatings for Fasteners

This specification covers the basic physical requirements and test methods for phosphate/oil and phosphate/organic corrosion protective coatings for fasteners such as nuts, clips, washers, and other ferrous threaded and non-threaded fasteners that require corrosion protection. The zinc phosphate treatment and subsequent protective coatings are classified into seven grades according to the following requirements: Grade 0A consists of a zinc phosphate coating with no additional sealer (dry); Grade 0B consists of a zinc phosphate coating with a dry organic sealer; Grades 0C, 0D, and I consist of a zinc phosphate coating with supplemental protective oil type compound; and Grades II and III consist of a zinc phosphate with a supplemental zinc-rich epoxy resin coating (with the addition of a clear organic topcoat for Grade II). These coatings may or may not have a decorative finish. The coatings shall meet the requirements specified for appearance, adhesion, corrosion resistance, coating flexibility, thread fit, and dry-to-touch characteristics. In addition, they shall also undergo humidity and coating thickness tests.1.1 This specification covers the basic requirements for six grades of corrosion protection for fasteners. Grade A consists of a heavy zinc phosphate coating with no additional sealer (dry), Grade B consists of a heavy zinc phosphate coating with a dry organic sealer, Grade C consists of a heavy zinc phosphate coating with supplemental dry-to-touch oil type compound, Grade D consists of a heavy zinc phosphate coating with supplemental protective oil type compound, Grade E consists of a grain-refined microcrystalline zinc phosphate with supplemental oil type compound, and Grade F consists of a manganese phosphate coating with supplemental oil type compound.1.2 This specification is intended primarily for fasteners such as nuts, clips, washers, and other ferrous threaded and non-threaded fasteners that require corrosion protection and lubrication.1.3 These coatings may or may not have a decorative finish.1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.