ISO 3076:2012

Round steel short link chains for general lifting purposes - Medium tolerance sling chains for chain slings - Grade 8

ISO 3076:2012 specifies the requirements for medium tolerance sling chains of grade 8 for use in chain slings and for general lifting purposes. They are round steel short link chains, electrically welded, heat treated and tested; they comply with the general conditions of acceptance of ISO 1834. The range of nominal sizes covered by ISO 3076:2012 is from 4 mm to 45 mm. They are for use in the temperature range of minus 40 °C to to plus 400 °C.

Chaînes de levage général en acier, de section ronde, à maillons courts — Chaînes de tolérance moyenne pour élingues — Classe 8

General Information

• Status: Published
• Publication Date: 17-Jun-2012
• ICS: 53.020.30 - Accessories for lifting equipment
• Technical Committee: ISO/TC 111/SC 1 - Chains and chain slings
• Drafting Committee: ISO/TC 111/SC 1 - Chains and chain slings
• Current Stage: 9093 - International Standard confirmed
• Start Date: 30-Jul-2024
• Completion Date: 13-Dec-2025

Relations

• Revises: ISO 3076:1984 - Short link chain for lifting purposes - Grade T (8), non-calibrated, for chain slings etc.
• Effective Date: 28-Feb-2009

Overview

ISO 3076:2012 specifies requirements for round steel short link sling chains - Grade 8 (medium tolerance) intended for chain slings and general lifting purposes. It covers electrically welded, heat-treated and tested short-link chains in nominal sizes from 4 mm to 45 mm, designed to operate in the temperature range –40 °C to +400 °C. Chains complying with ISO 3076 must also meet the general conditions of acceptance of ISO 1834.

Key topics and technical requirements

• Scope and sizes: Nominal material diameters covered: 4 mm to 45 mm; dimensions, pitch and widths are defined with tolerances.
• Chain types and weld limits: Two link types (Type 1 and Type 2) are defined with maximum permitted weld oversize - typically ≤10% in all directions for Type 1; Type 2 allows ≤10% perpendicular to the plane and ≤25% in other planes to maintain functioning and clearance.
• Material and metallurgy:
  • Steel produced by electric or oxygen-blown processes.
  • Fully killed steel with controlled sulfur, phosphorus and specified alloying (nickel, chromium, molybdenum where applicable) to ensure toughness and low-temperature ductility.
  • Aluminium content required to stabilize against strain-age embrittlement.
• Heat treatment: Hardened from above the Ac point and tempered - tempering at ≥400 °C for 1 hour is required (verification procedures included).
• Mechanical and safety tests:
  • Working Load Limits (WLLs), Manufacturing Proof Force (MPF) and Breaking Force (BF) are specified per nominal size (see standard tables).
  • Total ultimate elongation minimums (e.g., 20% for natural black finish).
  • Bend deflection requirements for individual links and toughness verified by Charpy/impact testing (ISO 148-1, ISO 14556).
  • Sampling, lot size and verification procedures for MPF, BF and impact tests are detailed.
• Marking and certification: Grade marking, identification and inspection marking rules and manufacturer’s certificate requirements are included.

Applications and users

ISO 3076 is directly applicable to:

• Chain sling manufacturers and component suppliers for producing Grade 8 sling chains.
• Rigging and lifting equipment designers, procurement/specifiers, and safety engineers who select chains for overhead lifting, hoisting and material handling.
• Inspection and testing laboratories performing mechanical and impact verification.
• Asset owners and fleet managers who require certified chain slings for safe lifting operations.

Practical benefits include consistent WLL determination, assured weld quality, validated low-temperature performance, and traceable marking and certification for compliance and safety.

Related standards

• ISO 1834 - Short link chain general conditions of acceptance
• ISO 3056 - Use and maintenance of chain slings
• ISO 148-1, ISO 14556 - Charpy/impact test methods
• ISO 16124, ISO 1035-1, ISO 643, ISO 7500-1 - material, dimensional and testing references

Keywords: ISO 3076, Grade 8 sling chains, short link chains, chain slings, working load limit, manufacturing proof force, breaking force, heat treatment, weld diameter, lifting safety.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 3076
Third edition
2012-06-15
Round steel short link chains for general
lifting purposes — Medium tolerance
sling chains for chain slings — Grade 8
Chaînes de levage général en acier, de section ronde, à maillons
courts — Chaînes de tolérance moyenne pour élingues — Classe 8
Reference number
©
ISO 2012
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO’s
member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
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Published in Switzerland
ii © ISO 2012 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General conditions of acceptance . 1
5 Dimensions . 1
5.1 Nominal size, d . 1
n
5.2 Material diameter and tolerance . 3
5.3 Weld diameter . 4
5.4 Length dimensionally affected by welding . 4
5.5 Pitch . 4
5.6 Width . 4
6 Material and manufacture . 4
6.1 Quality of material . 4
6.2 Heat treatment . 5
6.3 Working load limits (WLLs) . 5
6.4 Mechanical properties . 6
7 Verification of safety requirements .10
7.1 Size of lot and selection of samples .10
7.2 Manufacturing proof force, breaking force and total ultimate elongation .10
7.3 Bend deflection .10
7.4 Toughness of chain test material . 11
8 Marking .12
8.1 Grade marking .12
8.2 Identification marking .12
8.3 Inspection marking .12
9 Manufacturer’s certificate .12
Annex A (informative) Bases for calculation .13
Annex B (informative) Mass of sling chains .16
Annex C (informative) Designation system .17
Bibliography .18
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International
Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 3076 was prepared by Technical Committee ISO/TC 111, Round steel link chains, chain slings, components
and accessories, Subcommittee SC 1, Chains and chain slings.
This third edition cancels and replaces the second edition (ISO 3076:1984), which has been technically revised.
iv © ISO 2012 – All rights reserved

INTERNATIONAL STANDARD ISO 3076:2012(E)
Round steel short link chains for general lifting purposes —
Medium tolerance sling chains for chain slings — Grade 8
1 Scope
This International Standard specifies the requirements for medium tolerance sling chains of grade 8 for use in
chain slings and for general lifting purposes.
They are round steel short link chains (3 d ), electrically welded, heat treated and tested; they comply with the
n
general conditions of acceptance of ISO 1834.
NOTE 1 Butt welding and flash butt welding are listed in ISO 4063.
The range of nominal sizes covered by this International Standard is from 4 mm to 45 mm. They are for use in
the temperature range –40 °C to +400 °C.
NOTE 2 Concerning the use and maintenance of chain slings of grade 8, see ISO 3056.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced document
(including any amendments) applies.
ISO 148-1, Metallic materials — Charpy pendulum impact test — Part 1: Test method
ISO 643, Steels — Micrographic determination of the apparent grain size
ISO 1035-1, Hot-rolled steel bars — Part 1: Dimensions of round bars
ISO 1834, Short link chain for lifting purposes — General conditions of acceptance
ISO 7500-1, Metallic materials — Verification of static uniaxial testing machines — Part 1: Tension/compression
testing machines — Verification and calibration of the force-measuring system
ISO 14556, Steel — Charpy V-notch pendulum impact test — Instrumented test method
ISO 16124, Steel wire rod — Dimensions and tolerances
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1834 apply.
4 General conditions of acceptance
The sling chains shall comply with the requirements of ISO 1834 as well as those of this International Standard.
5 Dimensions
5.1 Nominal size, d
n
The nominal size, d , of the sling chain shall be one of the nominal sizes listed in Table 1, column 1, corresponding
n
to the nominal diameter of the steel wire in accordance with ISO 16124 or bar in accordance with ISO 1035-1
from which the sling chain is made.
Other nominal sizes may be used, provided the dimensions and tolerances are calculated in accordance
with Annex A.
NOTE Intermediate nominal chain sizes increase the potential of mismatch with mating components. Manufacturers
of sling chain and component assemblies are expected to ensure that the sling chain and components are compatible.
Table 1 — Dimensions
Dimensions in millimetres
1 2 3 4 5 6 7 8 9
Nominal Diameter Pitch Width Weld diameter
size tolerance
Internal External Internal
Tolerance Type 2 Types 1 Type 1 Types 1 Type 2
and 2 and 2
d p w w w d G
n n 1 3 4 w
min. max. min. max. max.
4 +0,08/–0,24 12 ±0,4 5,0 14,8 5,2 4,4 5,0
6 +0,12/–0,36 18 ±0,5 7,5 22,2 7,8 6,6 7,5
7 +0,14/–0,42 21 ±0,6 8,8 25,9 9,1 7,7 8,8
8 +0,16/–0,48 24 ±0,7 10,0 29,6 10,4 8,8 10,0
10 +0,20/–0,60 30 ±0,9 12,5 37,0 13,0 11,0 12,5
13 +0,26/–0,78 39 ±1,2 16,3 48,1 16,9 14,3 16,3
16 +0,32/–0,96 48 ±1,4 20,0 59,2 20,8 17,6 20,0
18 ±0,9 54 ±1,6 22,5 66,6 23,4 19,8 22,5
19 ±0,95 57 ±1,7 23,8 70,3 24,7 20,9 23,8
20 ±1,0 60 ±1,8 25,0 74,0 26,0 22,0 25,0
22 ±1,1 66 ±2,0 27,5 81,4 28,6 24,2 27,5
26 ±1,3 78 ±2,3 32,5 96,2 33,8 28,6 32,5
28 ±1,4 84 ±2,5 35,0 104,0 36,4 30,8 35,0
32 ±1,6 96 ±2,9 40,0 118,0 41,6 35,2 40,0
36 ±1,8 108 ±3,2 45,0 133,0 46,8 39,6 45,0
40 ±2,0 120 ±3,6 50,0 148,0 52,0 44,0 50,0
45 ±2,25 135 ±4,1 56,3 167,0 58,5 49,5 56,3
2 © ISO 2012 – All rights reserved

a)  Type 1
b)  Type 2
Key
p pitch (internal link length)
d measured diameter of the material, except at the weld
m
d measured diameter of the material at the weld (type 1) or weld dimension perpendicular to the plane of the link
w
(type 2)
G dimension in other planes (type 2)
e length affected by welding, on either side of the centre of the link
w internal link width away from the weld (type 2)
w external link width over the weld (types 1 and 2)
w internal link width at the weld (type 1)
Figure 1 — Chain link
5.2 Material diameter and tolerance
The definition of material diameter and method of measurement shall be in accordance with ISO 1834. The diameter
tolerance for the nominal sizes shall be as listed in Table 1, column 2, calculated in accordance with Annex A.
5.3 Weld diameter
The maximum diameter at the weld (see Figure 1 and Table 1, columns 8 and 9) shall not exceed the following:
— type 1: the maximum diameter at the weld shall not be in excess of 10 % above the nominal size in any direction;
— type 2: the maximum diameter at the weld shall not be in excess of 10 % above the nominal size in any
direction perpendicular to the plane of the link and 25 % in the other planes.
NOTE Type 1 eliminates functional problems, such as kinking or locking, by severely limiting the weld oversize to
10 % of the nominal diameter. Type 2 ensures freedom from these hazards by limiting the oversize beyond the 10 %
allowed under type 1 to certain areas of the link only (see Figure 1), thus providing clearance where required.
5.4 Length dimensionally affected by welding
The length dimensionally affected by welding, e, shall not extend by more than 0,6 d to either side of the centre
n
of the link (see Figure 1).
5.5 Pitch
The dimensions and tolerances for the pitch, p, shall be as given in Table 1, columns 3 and 4 and as shown in
Figure 1 calculated in accordance with Annex A.
5.6 Width
The dimensions for the widths, w, shall be as given in Table 1, columns 5, 6 and 7 and as shown in Figure 1
calculated in accordance with Annex A.
6 Material and manufacture
6.1 Quality of material
Within the limitations given in 6.1.1 to 6.1.4, it is the responsibility of the manufacturer of the sling chain to select
the type of steel to be used so that the finished sling chain, where suitably heat treated, complies with the
mechanical properties specified in this International Standard and also possesses adequate low-temperature
ductility and toughness to provide resistance against impact loading.
The low-temperature ductility and toughness shall be achieved either by complying with the alloying elements
specified in 6.1.5 or by complying with the toughness-testing requirements specified in 6.4.5.
6.1.1 Type of steel
The steel used shall be produced by the electric process or by an oxygen-blown process.
6.1.2 Deoxidation
The steel shall be fully killed and shall be made in conformity with a suitable deoxidation process in order to
obtain an austenitic grain size of 6 or finer where tested in accordance with ISO 643.
To ensure the sling chain is stabilized against strain-age embrittlement during service, the steel shall contain
at least 0,025 % aluminium, but not more than 0,050 % aluminium.
6.1.3 Weldability
The steel shall be of reliable weldable quality.
4 © ISO 2012 – All rights reserved

6.1.4 Sulfur and phosphorus content
The content of sulfur and phosphorus shall be restricted as specified in Table 2.
Table 2 — Sulfur and phosphorus content
Maximum mass content as determined by
cast analysis check analysis
Element
% %
Sulfur 0,020 0,025
Phosphorus 0,020 0,025
Sum of sulfur and phosphorus 0,035 0,045
6.1.5 Alloying elements
The steel shall contain alloying elements in sufficient quantities so that the finished sling chain, where heat
treated in accordance with 6.2, complies with the mechanical properties specified in this International Standard
but also possesses adequate low-temperature ductility and toughness to provided resistance to impact loading.
The steel shall contain nickel and at least one of the other elements in the minimum percentage shown in Table 3.
Table 3 — Content of alloying elements
Minimum mass content as determined by
Element cast analysis
%
Nickel 0,40
Chromium 0,40
Molybdenum 0,15
6.1.6 Finished condition
In its finished condition, as supplied to the manufacturer of the sling chain, the steel shall comply with the
requirements of 6.1.1 to 6.1.4 and 6.1.5, where appropriate, as determined by check analysis on the rod, wire
or finished link.
6.2 Heat treatment
Sling chains shall be hardened from a temperature above the Ac point and tempered before being subjected
to the manufacturing proof force (MPF), F . The tempering temperature shall be at least + 400 °C.
MP
The tempering conditions shall be at least as effective as the temperature of + 400 °C maintained for a
...