EN 12420:2024

SLOVENSKI STANDARD
oSIST prEN 12420:2022
01-oktober-2022
Baker in bakrove zlitine - Izkovki
Copper and copper alloys - Forgings
Kupfer und Kupferlegierungen - Schmiedestücke
Cuivre et alliages de cuivre - Pièces forgées
Ta slovenski standard je istoveten z: prEN 12420
ICS:
77.150.30 Bakreni izdelki Copper products
oSIST prEN 12420:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN 12420:2022
oSIST prEN 12420:2022
DRAFT
EUROPEAN STANDARD
prEN 12420
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2022
ICS 77.150.30 Will supersede EN 12420:2014
English Version
Copper and copper alloys - Forgings
Cuivre et alliages de cuivre - Pièces forgées Kupfer und Kupferlegierungen - Schmiedestücke
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 133.
If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 12420:2022 E
worldwide for CEN national Members.

oSIST prEN 12420:2022
prEN 12420:2022 (E)
Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Designations. 7
4.1 Material . 7
4.1.1 General . 7
4.1.2 Symbol . 7
4.1.3 Number . 7
4.2 Material condition . 8
4.3 Product . 8
5 Ordering information . 9
6 Requirements . 10
6.1 Composition . 10
6.2 Mechanical properties . 10
6.2.1 Hardness properties . 10
6.2.2 Tensile properties. 10
6.3 Electrical properties . 11
6.4 Resistance to dezincification . 11
6.5 Residual stress level . 11
6.6 Tolerances for die forgings . 11
6.6.1 General . 11
6.6.2 Tolerances for dimensions within the die cavity and for dimensions across the die
parting line . 12
6.6.3 Mismatch . 13
6.6.4 Flash projection . 13
6.6.5 Ejector marks. 14
6.6.6 Flatness tolerances . 15
6.6.7 Angular tolerances. 15
6.7 Tolerances for cored forgings . 16
6.8 Tolerances for hand forgings . 17
6.8.1 General . 17
6.8.2 Tolerances on dimensions . 17
6.8.3 Flatness tolerance . 18
6.8.4 Surface quality. 18
6.8.5 Drawings . 19
7 Sampling . 19
7.1 General . 19
7.2 Analysis . 19
7.3 Hardness, stress corrosion resistance, dezincification resistance and electrical
property tests . 19
8 Test methods . 20
8.1 Analysis . 20
oSIST prEN 12420:2022
prEN 12420:2022 (E)
8.2 Hardness test . 20
8.3 Electrical conductivity test . 20
8.4 Dezincification resistance test . 20
8.5 Stress corrosion resistance test . 20
8.6 Retests . 20
8.6.1 Analysis, hardness, electrical conductivity and dezincification resistance tests . 20
8.6.2 Stress corrosion resistance test . 21
8.7 Rounding of results . 21
9 Declaration of conformity and inspection documentation . 21
9.1 Declaration of conformity . 21
9.2 Inspection documentation . 21
10 Marking, labelling, packaging . 21
Annex A (informative) Recommended guidelines for design . 40
A.1 Introduction. 40
A.2 General information . 40
A.3 Guidelines for die forgings . 41
A.3.1 Drafts . 41
A.3.2 Web thicknesses . 41
A.3.3 Side wall thicknesses . 42
A.3.4 Rib design . 43
A.3.5 Cores . 45
A.3.6 Flash . 46
A.3.7 Transition radii . 47
A.3.8 Clamping lengths and clamping areas for finish machining . 48
A.3.9 Design for cross-sectional shapes . 49
A.3.10 Recommended machining allowances and total allowances . 49
A.4 Guidelines for hand forgings . 51
A.4.1 General . 51
A.4.2 General information . 52
A.4.3 Section changes and transitions . 52
A.4.4 Recommended machining allowances . 53
A.4.5 Total allowances per side of
...