Designation

This standard is issued under the fixed designation B633; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (ε) indicates an editorial change since the last revision or reapproval.

This standard has been approved for use by agencies of the U.S. Department of Defense.

INTRODUCTION

This specification provides a standard to order an electrodeposited zinc coating that mitigates corrosion of iron and steel articles in order to extend the service life of parts. The service life is reduced when such a coating stops protecting the iron or steel substrate resulting in corrosion of the substrate.

The pretreatment and plating process can introduce hydrogen that can cause internal hydrogen embrittlement in high strength steels causing loss of strength and ductility. It is generally agreed that steels below 1200 MPa are not susceptible to such embrittlement.

1. Scope*

1.1

This specification covers material and process requirements for electrodeposited zinc coatings applied to iron or steel articles to protect them from corrosion.

1.2

This specification is not intended to provide the design activity with all the background needed to properly specify their zinc coating requirements. The users of Specification B633 are encouraged to review this specification in its entirety including the appendices, and access the supplementary papers, other standards, and published literature referenced herein and within other related references.

1.3

The coatings are provided in four standard thickness classes (4.1), in the as-plated condition or with one of five types of supplementary finishes (4.2).

1.4

High strength metals, including high strength steels having a tensile strength greater than 1700 MPa (247 ksi, 46 HRC) should not be zinc electroplated in accordance with this specification.

1.5

It does not cover continuous processes for electrodeposited zinc coated steel wire or sheets (see Specification A591/ A591M for sheets).

1.6

For zinc electroplating of mechanical fasteners, the purchaser is encouraged to consider Specification F1941/ F1941M.

1.7

The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.8

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

1.9

This standard has been revised to address RoHS requirements that seek to limit the exposure of workers and the public from exposure to toxic metals. Additional types V and VI have been added to permit non-chromate passivate treatments to be used in replacement of hexavalent chromium.

1.10

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.

2. Referenced Documents

2.1

2.2

2.3

3. Terminology

3.1

4. Classification

4.1

4.2

5. Ordering Information

5.1

5.2

6. Materials and Manufacture

6.1

6.2

6.3

6.4

6.5

6.6

6.7

7. Coating Requirements

7.1

7.2

7.3

7.4

7.5

8. Sampling

8.1

8.2

9. Specimen Preparation

9.1

9.2

9.3

9.4

10. Test Methods

10.1

10.2

10.3

10.4

10.5

11. Rejection

11.1

12. Certification

12.1

12.2

13. Packaging and Packing

13.1

14. Keywords

14.1

SUPPLEMENTARY REQUIREMENTS

S1. Responsibility for Inspection

ASTM B633 - 23

Standard Specification for Electrodeposited Coatings of Zinc on Iron and Steel

Current

Published:

1 Jan 2023

1. Scope*

1. Scope^*