GB/T 5267.1-2023Fasteners - Electroplate coating (English PDF)

Foreword

This document was drafted in accordance with the rules given in GB/T 1.1-2020

"Directives for standardization - Part 1.Rules for the structure and drafting of

standardizing documents".

This document is Part 1 of GB/T 5267.The following parts of GB/T 5267 have already

been published.

- GB/T 5276.1, Fasteners -- Electroplate coating

- GB/T 5276.2, Fasteners -- Non-electrolytic zinc flake coating;

- GB/T 5276.3, Fasteners -- Hot-dip galvanized coating;

- GB/T 5276.4, Fastener surface treatment -- Corrosion-resistant stainless steel

passivation treatment.

This document supersedes GB/T 5267.1-2002 "Fasteners -- Electroplated Coatings".

Compared with GB/T 5267.1-2002, in addition to structural adjustments and editorial

changes, the main technical changes in this document are as follows.

a) The scope of application has been changed to include all fasteners, including

tapping screws, thread forming screws, washers, rivets, and clamps, and applies

to electroplated coatings with or without additional layers (conversion coatings,

sealing layers, surface coatings, lubricants) (see Chapter 1 of this Edition; Chapter

1 of Edition 2002);

b) A statement has been added indicating that the requirements of GB/T 5267.1 for

electroplated fasteners take precedence over other general national standards

involving electroplating (see Chapter 1 of this Edition);

c) All references to ISO 2081 (GB/T 9799) have been deleted;

d) The minimum corrosion resistance requirements (white corrosion and red rust)

have been increased (see Chapter 5 of this Edition);

e) The updated information on hydrogen embrittlement and preventive measures has

been added (see 4.4 and Annex B of this Edition);

f) The definitions as defined in GB/T 3099.3 have been added (see Chapter 3 of this

Edition);

g) Neutral salt spray testing (NSS) (see 5.2 of this Edition) and sulfur dioxide testing

(Kesternich) (see 5.3 of this Edition) have been added;

h) The requirements for measurability and assemblability have been added (see 6.2

of this Edition);

i) The test method for measuring thickness has been added, and the area for thickness

measurement has been more clearly defined (see 6.4 of this Edition);

j) The requirement for average batch thickness has been deleted (see Chapter 9 and

Annex D of Edition 2002);

k) A marking system for coating systems has been added (see Chapter 9 of this

Edition);

l) The mechanical and physical performance requirements and related test methods

have been added (see Chapter 7 of this Edition);

m) The information on the design and installation of electroplated fasteners has been

added (see Annex A of this Edition);

n) The information on the coating thickness and thread clearance of standard threads

has been added (see Annex D of this Edition);

o) The information regarding the corrosion resistance assessment of neutral salt

spray test chambers has been added (see Annex E of this Edition).

The modification of this document adopts ISO 4042.2022 "Fasteners -- Electroplate

coating systems".

The technical differences between this document and ISO 4042.2022, and the reasons

for these differences, are as follows.

- ISO 1891-2 is replaced by the normative reference GB/T 3099.3 (see Chapter 3) to

adapt to China's technical conditions;

- ISO 1456 is replaced by the normative reference GB/T 9797 (see Table 1, 7.1, Table

F.2) to adapt to China's technical conditions;

- ISO 2093 is replaced by the normative reference GB/T 12599 (see Table 1, 7.1) to

adapt to China's technical conditions;

- ISO 2082 is replaced by the normative reference GB/T 13346 (see Table 1, 7.1) to

adapt to China's technical conditions;

- ISO 15330 is replaced by the normative reference GB/T 3098.17 (see 4.4.6, B.6)

to adapt to China's technical conditions;

- ISO 9227 is replaced by the normative reference GB/T 10125 (see 5.2, Table 8,

A.1.4.1, Annex C, Annex E) to adapt to China's technical conditions;

- ISO 1502 is replaced by the normative reference GB/T 3934 (see 6.2.2) to adapt to

China's technical conditions;

Fasteners -- Electroplate coating

1 Scope

This document specifies requirements for steel fasteners with electroplated coatings and

coating systems. The requirements related to dimensional properties also apply to

fasteners made of copper or copper alloys.

It also specifies internal hydrogen embrittlement requirements (see 4.4) and provides

recommendations for reducing the risk of hydrogen embrittlement (see Annex B).

It mainly applies to fasteners with zinc and zinc alloy coating systems (zinc, zinc-nickel,

zinc-iron) and cadmium, primarily intended for corrosion protection and other

functional properties.

- with or without conversion coating,

- with or without sealant,

- with or without top coat,

- with or without lubricant (integral lubricant and/or subsequently added lubricant).

In this document, only the dimensional requirements for standard threaded fasteners

apply to other coating and coating systems (tin, tin-zinc, copper-tin, copper-silver,

copper, silver, copper-zinc, nickel, nickel-chromium, copper-nickel, copper-nickel-

chromium).

This document's requirements for electroplated fasteners take precedence over other

documents concerning electroplating.

This document applies to standard threaded bolts, screws, studs, and nuts, as well as

non-standard threaded fasteners and non-threaded fasteners such as washers, pins,

clamps, and rivets.

NOTE. Electroplating is also applied to stainless steel fasteners, e.g. for the purpose of lubrication

in order to avoid galling.

Design and assembly information for coated fasteners can be found in Annex A.

This document does not specify the weldability or coating properties of the fasteners.

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