This specification covers the basic requirements and associated test methods for water-based corrosion protective zinc/aluminum dispersion inorganic basecoats, and optional sealers and topcoats for fasteners. The basecoat can contain chrome (C) or be non-chrome (NC). These coatings are applied to ferrous parts by conventional dip-spin, dip-drain, or spray methods, which can be handled through a cleaning, coating, and baking operation, and which are not adversely affected by baking temperatures up to 626 °F. The coatings are classified into six grades (Grades 1 to 6) according to the required minimum basecoat thickness, and when tested, shall conform accordingly to appearance, adhesion, corrosion resistance, blister, thread fit, and hydrogen embrittlement requirements. The coating process does not induce the possibility of internal hydrogen embrittlement provided that the fasteners have not been cleaned or pre-treated with an acid or phosphate. Alkaline cleaning or vapor degreasing is required along with shot blasting to remove rust or scale. No metric equivalents are presented in this specification.

This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.

1. Scope

1.1 This specification covers the basic requirements for water-based zinc/aluminum dispersion inorganic basecoats and optional sealers and topcoats for fasteners. The basecoat can contain chrome (C) or be non-chrome (NC).

1.2 These coatings are applied by conventional dip-spin, dip-drain, or spray methods to ferrous parts which can be handled through a cleaning, coating, and baking operation, and which are not adversely affected by baking temperatures up to 626°F.

1.3 The coating process does not induce the possibility of internal hydrogen embrittlement providing that the fasteners have not been cleaned or pre-treated with an acid or phosphate. Alkaline cleaning or vapor degreasing is required along with shot blasting to remove rust or scale.

1.4 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Index Terms

aluminum; chrome; coating; corrosion; dip spin; fasteners; protection; resistance ; rust; sealer; zinc; Chromium electroplating; Corrosion-resistant coatings--specifications; Electrodeposited Cr coatings--specifications; Fasteners (metal)--specifications; Inorganic coatings--specifications; Zinc electrodeposited coatings--specifications;

ICS Code

ICS Number Code 21.060.01 (Fasteners in general); 25.220.40 (Metallic coatings)

Citing ASTM Standards

[Back to Top]