National foreword

This British Standard is the UK implementation of EN 4729:2017.

The UK participation in its preparation was entrusted to Technical Committee ACE/65, Non-metallic materials for aerospace purposes.

A list of organizations represented on this committee can be obtained on request to its secretary.

This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 September 2017.

This European Standard was approved by CEN on 14 May 2017.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.

European foreword

This document (EN 4729:2017) has been prepared by the Aerospace and Defence Industries Association of Europe - Standardization (ASD‑STAN).

After enquiries and votes carried out in accordance with the rules of this Association, this Standard has received the approval of the National Associations and the Official Services of the member countries of ASD, prior to its presentation to CEN.

This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by March 2018, and conflicting national standards shall be withdrawn at the latest by March 2018.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.

1 Scope

This European Standard specifies trivalent chromium based chemical conversion coatings for aluminium and aluminium alloys. It covers the application by bath but also by touch-up. It doesn’t give complete in‑house process instructions; these shall be given in the manufacturers detailed process instructions.

2 Purpose of process

3 Normative references

4 Terms and definitions

5 Applicability and limitations of the process

6 Classification

6.1 Coating weight

6.2 Materials

7 Requirements

7.1 Process requirements

8 Main technical engineering requirements

8.1 General

8.2 Appearance

8.3 Coating weight

8.4 Corrosion resistance

8.5 Adhesion

8.6 Electrical contact resistance

9 Quality requirements

9.1 Approval of the processor

9.2 Process approval

9.3 General points

9.4 Periodic tests

9.5 Periodic chemical analysis

9.6 Parts acceptance inspections

9.7 Test specimen

9.8 Baths

10 Quality assurance

10.1 Approval of the processor

10.2 Series production approval

10.3 Acceptance

11 Health, safety and environmental aspects

12 Designation

BS EN 4729:2017

Aerospace series. Trivalent chromium based chemical conversion coatings for aluminium and aluminium alloys

Current

Published:

30 Sep 2017