EN 818-7:2002
(Main)Short link chain for lifting purposes - Safety - Part 7: Fine tolerance hoist chain, Grade T (Types T, DAT and DT)
Short link chain for lifting purposes - Safety - Part 7: Fine tolerance hoist chain, Grade T (Types T, DAT and DT)
This European Standard specifies the requirements related to safety for hoist chain, Grade T (type T quenched and tempered and types DAT and DT case hardened), for use in serial chain hoists manual and power driven.
Type DAT and type DT hoist chains possess surface hardnesses greater than core hardness and are used for power driven chain hoists to offer greater resistance to wear.
Type DT hoist chain differs from DAT hoist chain in having higher surface hardness and/or greater case depth to optimise wear resistance.
The standard is applicable to electrically welded round steel short link hoist chains conforming to EN 818-1.
The range of nominal size of hoist chains covered by this European Standard is from 4 mm to 22 mm.
The hazards covered by this European Standard are identified in clause 4.
Kurzgliedrige Rundstahlketten für Hebezwecke - Sicherheit - Teil 7: Feintolerierte Hebezeugketten, Güteklasse T (Ausführung T, DAT und DT)
Dieser Teil von EN 818 legt Anforderungen in bezug auf Sicherheit von Hebezeugketten der Güteklasse T (Ausführung T vergütet und Ausführungen DAT und DT oberflächengehärtet) für den Einsatz in Serienhebezeugen und anderen Hebevorrichtungen fest. Hebezeugketten der Ausführungen DAT und DT besitzen eine höhere Oberflächenhärte als die Kernhärte und bieten einen höheren Verschleißwiderstand in motorisch angetriebenen Serienhebezeugen.
Chaînes de levage à maillons courts - Sécurité - Partie 7: Chaînes de tolérance serrée pour les palans, classe T (Types T, DAT et DT)
La présente Norme européenne spécifie les prescriptions relatives à la sécurité des chaînes pour palans, de classe T, (type T trempé et revenu et types DAT et DT cémentés), pour une utilisation avec des palans à chaîne de série actionnés manuellement ou électriquement.
Les chaînes pour palans de types DAT et DT ont une dureté de surface supérieure à la dureté de l'âme et sont utilisées pour des palans à chaîne motorisés afin d'offrir une plus grande résistance à l'usure.
Les chaînes pour palans de type DT sont différentes des chaînes pour palans de type DAT car elles ont une dureté de surface plus importante et/ou une épaisseur de couche cémentée plus importante afin d'optimiser la résistance à l'usure.
La présente norme s'applique aux chaînes pour palans en acier à maillons courts soudés électriquement conformément à l'EN 818-1.
La plage de dimension nominale des chaînes pour palans couvertes par la présente Norme européenne est comprise entre 4 mm et 22 mm.
Les phénomènes dangereux couverts par la présente Norme européenne sont identifiés à l'article 4.
Kratkočlene okrogle verige za dviganje - Varnost - 7. del: Verige za dvigala, izdelane v ozkih tolerancah, razred T (vrste T, DT in DAT)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 818-7:2002
01-november-2002
.UDWNRþOHQHRNURJOHYHULJH]DGYLJDQMH9DUQRVWGHO9HULJH]DGYLJDOD
L]GHODQHYR]NLKWROHUDQFDKUD]UHG7YUVWH7'7LQ'$7
Short link chain for lifting purposes - Safety - Part 7: Fine tolerance hoist chain, Grade T
(Types T, DAT and DT)
Kurzgliedrige Rundstahlketten für Hebezwecke - Sicherheit - Teil 7: Feintolerierte
Hebezeugketten, Güteklasse T (Ausführung T, DAT und DT)
Chaînes de levage a maillons courts - Sécurité - Partie 7: Chaînes de tolérance serrée
pour les palans, classe T (Types T, DAT et DT)
Ta slovenski standard je istoveten z: EN 818-7:2002
ICS:
53.020.30 Pribor za dvigalno opremo Accessories for lifting
equipment
SIST EN 818-7:2002 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
EUROPEAN STANDARD
EN 818-7
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2002
ICS 53.020.30
English version
Short link chain for lifting purposes - Safety - Part 7: Fine
tolerance hoist chain, Grade T (Types T, DAT and DT)
Chaînes de levage à maillons courts - Sécurité - Partie 7: Kurzgliedrige Rundstahlketten für Hebezwecke - Sicherheit
Chaînes de tolérance serrée pour les palans, classe T - Teil 7: Feintolerierte Hebezeugketten, Güteklasse T
(Types T, DAT et DT) (Ausführung T, DAT und DT)
This European Standard was approved by CEN on 8 November 2001.
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 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 Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2002 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 818-7:2002 E
worldwide for CEN national Members.
---------------------- Page: 2 ----------------------
EN 818-7:2002 (E)
Contents
page
Foreword .3
Introduction .4
1 Scope.4
2 Normative references.5
3 Terms and definitions.5
4 Hazards .6
5 Safety requirements.7
6 Verification of safety requirements.14
7 Marking.18
8 Manufacturer's certificate.18
9 Information for use and assembly of the hoist chain into the hoist.18
Annex A (normative) Calculation of dimensions, working load limits and mechanical
properties.20
Annex B (normative) Selection criteria for fine tolerance chain for power driven hoists.
Types T, DAT and DT .23
Annex C (informative) Designation system for hoist chain - grade T .31
Annex D (informative) Approximate mass of Grade T hoist chain .32
Annex E (informative) Chain use .33
Annex ZA (informative) Relationship of this document with EC Directives.34
Bibliography.35
2
---------------------- Page: 3 ----------------------
EN 818-7:2002 (E)
Foreword
This document EN 818-7:2002 has been prepared by Technical Committee CEN /TC 168 "Chains,
ropes, webbings, slings and accessories", the secretariat of which is held by BSI.
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 August 2002, and conflicting national standards shall
be withdrawn at the latest by August 2002.
This document has been prepared under a mandate given to CEN by the European Commission and
the European Free Trade Association, and supports essential requirements of EC Directive(s).
For relationship with EC Directive(s), see informative annex ZA, which is an integral part of this
document.
The other parts of EN 818 are:
Part 1: General conditions of acceptance
Part 2: Medium tolerance chain for chain slings - Grade 8
Part 3: Medium tolerance chain for chain slings - Grade 4
Part 4: Chain slings - Grade 8
Part 5: Chain slings - Grade 4
Part 6: Chain slings - Specification for information for use and maintenance to be provided by
the manufacturer.
This is the first edition of this part of EN 818.
The annexes A and B are normative. The annexes C, D, E and ZA are informative.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Czech
Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta,
Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.
3
---------------------- Page: 4 ----------------------
EN 818-7:2002 (E)
Introduction
This European Standard has been prepared to be a harmonized standard to provide one means of
conforming with the essential safety requirements of the Machinery Directive and associated EFTA
regulations.
These chains are intended for use in serial hoists. The multiple pitch is fine toleranced.
The extent to which hazards are covered is indicated in the scope of this European Standard. In
addition, lifting equipment should conform as appropriate to EN 292 for hazards which are not
covered by this standard.
Annex A is normative and gives the bases for the calculation of the dimensions and the mechanical
properties of hoist chains.
Annex B is normative and gives selection criteria for the nominal size of hoist chains, Grade T, types T,
DAT and DT for serial hoists.
Annex C is informative and gives a designation system for recording the identifying features of fine
tolerance short link chain Grade T. Since this system is not widely used it has been included in this
first edition of this standard as an informative annex; however, should its use become more generally
accepted then the status of the information would need to be reviewed.
1 Scope
This European Standard specifies the requirements related to safety for hoist chain, Grade T (type T
quenched and tempered and types DAT and DT case hardened), for use in serial chain hoists manual
and power driven.
Type DAT and type DT hoist chains possess surface hardnesses greater than core hardness and are
used for power driven chain hoists to offer greater resistance to wear.
Type DT hoist chain differs from DAT hoist chain in having higher surface hardness and/or greater case
depth to optimise wear resistance.
The standard is applicable to electrically welded round steel short link hoist chains conforming to
EN 818-1.
The range of nominal size of hoist chains covered by this European Standard is from 4 mm to 22 mm.
The hazards covered by this European Standard are identified in clause 4.
4
---------------------- Page: 5 ----------------------
EN 818-7:2002 (E)
2 Normative references
This European Standard incorporates, by dated or undated reference provisions from other publications.
These normative references are cited at the appropriate places in the text, and the publications are listed
hereafter. For dated references, subsequent amendments to or revisions of any of these publications
apply to this European Standard only when incorporated in it by amendment or revision. For undated
references, the latest edition of the publication referred to applies (including amendments).
EN 292-1:1991, Safety of machinery – Basic concepts – General principles for design – Part 1: Basic
terminology, methodology.
EN 292-2:1991/A1:1995, Safety of machinery – Basic concepts – General principles for design – Part 2:
Technical principles and specifications.
EN 818-1:1996, Short link chain for lifting purposes – Safety – Part 1: General conditions of acceptance.
EN 1050:1996, Safety of machinery – Principles for risk assessment.
EN ISO 7500-1, Metallic materials - Verification of static uniaxial testing machines - Part 1:
Tension/compression testing machines (ISO 7500-1:1999).
EN 10025, Hot rolled products of non-alloy structural steels; technical delivery conditions (includes
amendment A1:1993).
ISO 643, Steels – Micrographic determination of the ferritic or austenitic grain size.
ISO 4301-1, Cranes and lifting appliances – Classification – Part 1: General.
ISO 6507-1, Metallic materials – Vickers hardness test – Part 1: Test method.
ISO 4965, Axial load fatigue testing machines - Dynamic force calibration - Strain gauge technique.
3 Terms and definitions
For the purposes of this European Standard the terms, definitions and symbols given in EN 818-1 apply.
5
---------------------- Page: 6 ----------------------
EN 818-7:2002 (E)
4 Hazards
The release of a load due to failure of hoist chain puts at risk either directly or indirectly the safety or
health of those persons within the danger zone of lifting equipment.
In order to provide the necessary strength and durability of hoist chain, this European Standard lays down
requirements for the design, selection of materials of construction and testing to ensure that specified
levels of performance are met.
Fatigue failure has not been identified as a hazard for type T chain when hoist chain selected according
to annex B and having the specified levels of performance and design given in this European Standard is
used in serial hoists.
Fatigue failure has been identified as a hazard for hoist chains types DAT and DT used in power driven
hoists. Therefore this European Standard specifies levels of design and performance, with particular
reference to fatigue resistance.
Since failure can be caused by the incorrect choice of grades and specification of lifting hoist chain this
European Standard also gives the requirements for marking and the manufacturers certificate.
Dimensional incompatibility between the hoist chain and mating parts of the hoist (chain wheel, chain
guide and loading device) may lead to premature failure and this European Standard contains
dimensional requirements for correct assembly and fit.
Table 1 lists those hazards, which require action to reduce risk identified by risk assessment as being
specific and significant for hoist chain of Grade T Types T, DAT, DT.
Table 1 — Hazards and associated requirements
Hazards identified in annex A of Relevant clause of annex A of Relevant clause/subclause
EN 1050:1996 EN 292-2:1991/A1:1995 of this standard
1.e Mechanical hazard due to 1.3.2 } 5
inadequacy of strength 4.1.2.3 }
4.1.2.4 }
4.2.4 6
1.7.3 }
4.3.1 } 7
1.5 (Types DAT, DT only) - 5.5.6
Fatigue failure and 6.2.7
6
---------------------- Page: 7 ----------------------
EN 818-7:2002 (E)
5 Safety requirements
5.1 General
The hoist chains shall conform to the requirements of EN 818-1.
5.2 Dimensions
5.2.1 General
A selection of nominal sizes and dimensions is given in 5.2.2 and 5.2.4. Other nominal sizes may be
used, provided that nominal sizes shall not exceed the range specified in 5.2.2 and that the dimensions
and tolerances are calculated in accordance with annex A.
Whilst the nominal link pitch p is based upon 3 d (where d is the nominal size of the hoist chains) this
n n n
may be varied but shall not exceed the limits 2,6 d to 3,2 d . The nominal link pitch p shall be subject to
n n n
the tolerances specified in annex A.
NOTE Compatibility between the hoist chain and the mating parts of the hoist requires agreement on the
nominal size and dimensions and on the distribution of tolerances between the chain manufacturer and the hoist
manufacturer.
5.2.2 Nominal size d
n
The nominal size shall not be below 4 mm or above 22 mm, a selection of nominal sizes is listed in
Table 2.
5.2.3 Tolerances on material diameter
The tolerances on material diameter for the selected nominal sizes shall be as listed in Table 2. These
and all other nominal size material diameter tolerances shall be calculated in accordance with A.1.
5.2.4 Pitch and widths
The dimensions and tolerances of the 3 d pitch and the width for the selected nominal sizes shall be
n
as listed in Table 2. The dimensions and tolerances of the pitch and width shall be calculated in
accordance with A.1.
These dimensions and tolerances and all other nominal size and pitch ranges and tolerances of multiple
pitch lengths, shall be calculated in accordance with A.1.
The tolerances of multiple pitch lengths shall be calculated in accordance with A.1.
7
---------------------- Page: 8 ----------------------
EN 818-7:2002 (E)
Table 2 — Selected dimensions
Dimensions in millimetres
Pitch Width Gauge length of Weld
11 x p diameter
n
1 1)
Nominal Material tolerance internal external tolerance d
s
size diameter w w
3 2
d tolerance p min. max. max.
n n
4 ± 0,2 12 0,25 4,8 13,6 132 0,6 4,3
5 ± 0,2 15 0,3 6,0 17,0 165 0,8 5,4
6 ± 0,2 18 0,35 7,2 20,4 198 1,0 6,5
7 ± 0,3 21 0,4 8,4 23,8 231 1,1 7,6
8 ± 0,3 24 0,5 9,6 27,2 264 1,3 8,6
9 ± 0,4 27 0,5 10,8 30,6 297 1,4 9,7
10 ± 0,4 30 0,6 12,0 34,0 330 1,6 10,8
11 ± 0,4 33 0,6 13,2 37,4 363 1,7 11,9
12 ± 0,5 36 0,7 14,4 40,8 396 1,9 13,0
13 ± 0,5 39 0,8 15,6 44,2 429 2,1 14,0
14 ± 0,6 42 0,8 16,8 47,6 462 2,2 15,1
16 ± 0,6 48 0,9 19,2 54,4 528 2,5 17,3
18 ± 0,9 54 1,0 21,6 61,2 594 2,9 19,4
20 ± 1,0 60 1,2 24,0 68,0 660 3,2 21,6
22 ± 1,1 66 1,3 26,4 74,8 726 3,5 23,8
1)
These tolerances are usually divided into + 2/3 and – 1/3 for both the individual link and the
standard gauge length.
5.2.5 Weld diameter
The maximum diameter at the weld for the selected nominal sizes shall be as in Table 2 and shall be
calculated in accordance with annex A. The maximum diameter at the weld shall not be in excess of 8 %
above the nominal size in any direction. The thickness of the steel at the weld shall nowhere be less than
the actual diameter of the steel adjacent to the weld.
5.2.6 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
n
centre of the link (see Figure 1).
8
---------------------- Page: 9 ----------------------
EN 818-7:2002 (E)
Key
1 Traverse centre line of the link
l is the multiple pitch length
p is the pitch
d is the material diameter as measured
m
d is the weld diameter
s
e is the length dimensionally affected by welding
w is the internal width at the weld
3
w is the external width over the weld
2
Figure 1 — Link and hoist chains dimensions
9
---------------------- Page: 10 ----------------------
EN 818-7:2002 (E)
5.3 Materials and heat treatment
5.3.1 Quality of material
5.3.1.1 General
Within the limitations given in 5.3.1.2 to 5.3.1.4 the hoist chain manufacturer shall select the type of steel
to be used so that the finished hoist chain, when heat-treated, meets the mechanical properties specified
in this European Standard.
5.3.1.2 Type of steel
The steel used shall be produced by an electric process or by an oxygen blown process.
5.3.1.3 Deoxidation
The steel shall be fully killed, as defined in EN 10025 and shall be stabilized against strain age
embrittlement and shall have an austenitic grain size of 5 or finer when tested in accordance with
ISO 643.
5.3.1.4 Chemical composition
The steel shall contain alloying elements in sufficient quantities so that the finished hoist chain, when heat
treated in accordance with 5.3.2, not only conforms to the mechanical properties specified in this
European Standard but also possesses adequate low temperature ductility and toughness to provide
resistance to impact loading. The hoist chain shall not be adversely affected by temperatures down to
those listed for each hoist chain type in Table 9.
The steel shall contain nickel and at least one of the other elements in the minimum percentages shown
in Table 3.
Table 3 — Chemical composition - alloying elements
Element Minimum mass content % as determined by cast analysis for
type T type DAT type DT
1)
Nickel 0,40 0,7 0,9
Chromium 0,40 0,40 0,40
Molybdenum 0,15 0,15 0,15
1)
The higher surface hardness and/or greater case depth requires a higher nickel content to avoid
brittleness.
To ensure that hoist chain is stabilized against strain-age embrittlement during service, the steel shall
contain at least 0,025 % aluminium.
The steel shall contain no more sulfur and phosphorus than the limits given in Table 4.
Table 4 — Sulfur and phosphorus content
Element Maximum mass content % as determined by
Cast analysis Check analysis
Sulfur 0,020 0,025
Phosphorus 0,020 0,025
Sum of Sulfur + Phosphorus 0,035 0,045
10
---------------------- Page: 11 ----------------------
EN 818-7:2002 (E)
5.3.2 Heat treatment
Hoist chains of all types shall be hardened and/or case hardened from a temperature above the AC3
point and tempered before being subjected to the manufacturing proof force.
5.4 Working load limits (WLL)
The working load limits for the selected nominal sizes of hoist chains shall be as given in Table 5.
NOTE The limits given in Table 5 have been calculated in accordance with annex A.
For nominal sizes not included in Table 5 the working load limits shall be calculated in accordance
with annex A.
Additional stresses imposed on the hoist chain by the operation of power driven hoists shall be taken
into account in selecting the nominal size for a particular application. In the case of hoist chain for
power driven hoists, annex B shall be used for the calculation.
Table 5 — Working load limits (WLL)
Nominal size d Chain type T Chain type DAT Chain type DT
n
mm ttt
4 0,5 0,4 0,25
5 0,8 0,63 0,4
6 1,1 0,9 0,56
7 1,5 1,2 0,75
82 1,6 1
9 2,5 2 1,25
10 3,2 2,5 1,6
11 3,8 3, 1,9
12 4,5 3,6 2,2
13 5,3 4,2 2,6
14 6 5 3
16 8 6,3 4
18 10 8 5
20 12,5 10 6,3
22 15 12,5 7,5
2 1)
mean stress N/mm 200 160 100
1)
Only for hand operated hoists. For power driven hoists: see annex B, Table B.1.
11
---------------------- Page: 12 ----------------------
EN 818-7:2002 (E)
5.5 Mechanical properties
5.5.1 Manufacturing proof force (MPF)
All hoist chains shall be subjected to the manufacturing proof force calculated on the basis given in
annex A. For the selected nominal sizes values are given in Table 6.
NOTE The formula and rounding rules for the calculation are also given in annex A.
Table 6 — Manufacturing proof forces and breaking forces
Nominal size Manufacturing proof force (MPF) Breaking force (BF)
d kN kN
n
mm min. min.
4 12,6 20,1
5 19,6 31,4
6 28,3 45,2
7 38,5 61,6
8 50,3 80,4
9 63,6 102
10 78,5 126
11 95 152
12 113 181
13 133 212
14 154 246
16 201 322
18 254 407
20 314 503
22 380 608
5.5.2 Breaking force (BF) and total ultimate elongation (A)
Samples of hoist chain in the finished condition shall have a breaking force at least equal to that
calculated on the basis given in annex A and on completion of the tensile test the minimum total ultimate
elongation shall be in accordance with the values given in Table 7.
12
---------------------- Page: 13 ----------------------
EN 818-7:2002 (E)
5.5.3 Bend deflection
Single link samples of type T shall withstand the minimum deflection specified in Table 7 and shall be
free from visible defects.
Sample links of types DAT and DT shall withstand a force F equivalent to 2,5 times the working load limit
0
of the hoist chain as given in 5.4 without fracture. Surface cracks or visible defects shall not be
considered to constitute fracture.
5.5.4 Surface hardness
The surface hardness at each of the three measuring points as shown in Figure 3 for all hoist chain types
shall be at least equal to the value specified in Table 7.
Table 7 — Total ultimate elongation, bend deflection and surface hardness
hoist chain types
TDAT DT
1)
Total ultimate elongation A %min10 10 5
2) 2)
Deflection f mm min0,8 d - -
n
3)
Surface hardness min
d < 7 mm, HV 5 360 500 550
n
d = 7 mm to 11 mm, HV 10 360 500 550
n
d > 11 mm, HV 10 360 450 500
n
1)
As specified in 6.4.4 of EN 818-1:1996, except L , the original internal length of the test sample, is
0
used instead of L , the nominal internal length.
n
2)
See 5.5.3.
3)
For measuring points see 6.2.5.
5.5.5 Case depth
For fine tolerance hoist chain types DAT and DT, the case depth, when measured in accordance with the
type test in 6.2.6, shall be within the limits related to nominal size d given in Table 8.
n
Table 8 — Case depth
Nominal
d hoist chain types
n
mm DAT DT
< 8 (0,04 ± 0,01) d (0,05 ± 0,01) d
n n
(0,03 ± 0,01) d (0,04 ± 0,01) d
8
n n
5.5.6 Fatigue resistance
6
Fine tolerance hoist chain types DAT and DT shall withstand at least 2 10 cycles of application of the
stress range specified in 6.2.7 without failure.
13
---------------------- Page: 14 ----------------------
EN 818-7:2002 (E)
6 Verification of safety requirements
6.1 Qualification of personnel
All testing and examination shall be carried out by a competent person.
6.2 Type tests
6.2.1 General
Prior to the manufacture of production quantities of each size and type of chain the following tests
shall be carried out with satisfactory results.
Any change in dimensions, chemical composition, carburising conditions or heat treatment, outside
usual manufacturing tolerances, will necessitate a repeat of all the type tests.
6.2.2 Dimensions
Measurements shall be taken on each individual link in an 11 link length of chain and the
requirements of 5.2 shall be met. The 11 link gauge length shall also be measured and shall conform
to 5.2
6.2.3 Manufacturing proof force, breaking force and total ultimate elongation
Three chain samples shall be subjected to static tensile testing as specified in EN 818-1. On
completion of the static tensile tests the requirements specified in 5.5.1 and 5.5.2 shall be met.
6.2.4 Bend deflection
Three single links of chain shall be subjected to bend testing as specified in EN 818-1.
Each single link sample of type T chain shall be bent by a deflection f as given in Table 7 and shown
in Figure 2. Each single link sample of types DAT and DT chain shall be loaded with force F as
o
specified in 5.5.3. Following removal of the force the link samples shall be examined by a competent
person and the requirements of 5.5.3 shall be met.
6.2.5 Surface hardness test
Three single links of chains shall be subjected to surface hardness testing carried out in accordance
with ISO 6507-1 with measurements taken at three points as shown in Figure 3. Special jigging shall
be used to ensure that the curvature of the link surface does not affect the validity of the
measurements taken. Each result shall meet the requirements of 5.5.4.
14
---------------------- Page: 15 ----------------------
EN 818-7:2002 (E)
Figure 2 — Bend deflection f Figure 3 — Hardness test, measuring points
6.2.6 Case Depth Determination – Types DAT and DT
Three single links of chain shall be subjected to tests to determine core hardness and case depth.
Each of the three separate sample links shall be cut through the crown of the link as indicated in
Figure 4 such that the surface to be tested is on the centre line of the link with the intrados identified.
Each sample shall be mounted in hard metallographic plastic and prepared to at least a 6 μm finish.
Vickers hardness measurements, using a 5 N test force, shall be carried out inwards from the intrados
by a competent person, in accordance with the procedures in ISO 6507-1. Care shall be taken in
selecting the longitudinal and lateral spacing of the test impressions to ensure that an accurate plot of
hardness against position is obtained. The inward series of measurements shall be continued until it is
apparent that a minimum hardness level has been reached.
A reference line shall be constructed on the plot at a level equivalent to 20 points Vickers above the
estimated core hardness. The position equivalent to the intersection of this reference line with the plot
of hardness against position shall be considered as the total case depth.
The estimated core hardness is the hardness measured at a position equivalent to 3 x 0,06 d in from
n
the outer surface.
Each determination of case depth shall meet the requirements of 5.5.5.
15
---------------------- Page: 16 ----------------------
EN 818-7:2002 (E)
Key
1 Transverse section
2 Diameter along which measurements are taken
3 X = Intrados
Figure 4 — Hardness test for case depth determination, link arrangement
6.2.7 Fatigue resistance test – Types DAT and DT.
Three 5-link samples shall be subjected to fatigue testing.
The frequency of the stress applied shall be 5 Hz to 10 Hz, and the testing machine shall conform to
ISO 4695 and Class 3 of EN ISO 7500-1.
The stress level applied during each cycle shall be as follows:
2
maximum stress level ( ) 200 N/mm
max
2
mean stress level 120 N/mm
2
minimum stress level ( )40 N/mm
min
Each sample shall meet the requirements of 5.5.6. Samples which fail in the area of the machine grips
shall be discarded and that test repeated.
6.3 Type tests – Acceptance criteria
The requirements of 6.2.2, 6.2.5 and 6.2.6 shall be met by each sample of each size and type of chain
tested.
For 6.2.3, 6.2.4 and 6.2.7, if one sample fails to meet the requirements two further samples of the
same chain shall be tested. If both of these re-tests are satisfactory then the type test requirements
have been met.
Once all type tests have been satisfactorily completed for each size and type of chain in question then
full production can commence.
16
---------------------- Page: 17 ----------------------
EN 818-7:2002 (E)
6.4 Production tests
6.4.1 General
The size of the lot from which samples shall be selected shall be 200 m. An excess fraction on the
length of the lot shall be considered as a separate lot. For types DAT and DT, if the batch quantity of
the furnace used for the case hardening process is less than 200 m, this quantity shall be considered
as a lot. Samples shall be selected as specified in EN 818-1.
6.4.2 Dimensions
The number of samples for dimensional checking shall be related to chain size as specified in EN
818-1 and each sample shall consist of an 11-link length of chain.
Measurements shall be taken on each individual link in each length and the requirements of 5.2 shall
be met.
The 11-link gauge length shall also be measured and shall conform to 5.2.
6.4.3 Manufacturing proof force
The testing machine and test procedure for the tensile test shall be as specified in EN 818-1. All of the
hoist chain shall be tested and shall be subjected to the manufacturing proof force specified in 5.5.1.
6.4.4 Breaking force and total ultimate elongation
The testing machine and test procedure for the tensile test shall be as specified in EN 818-1.
On completion of the static tensile test the requirements of 5.5.2 shall be met.
6.4.5 Bend Deflection
The test equipment and procedure shall be as specified in EN 818-1.
Each single link sample of type T shall be bent by a deflection f, as given in Table 7 and shown in
Figure 2.
F as specified in
Single link samples of types DAT and DT shall be correspondingly loaded with force
o
5.5.3. Following the removal of the force, the link sample shall be examined by a competent person
and the requirements of 5.5.3 shall be met.
NOTE Where necessary a surface coating may be removed after the bend test to enable this examination to
be carried out.
6.4.6 Surface hardness test
The number of samples for surface hardness testing shall be related to chain size as specified in
EN 818-1 and each sample shall consist of three single links.
Each sample link shall be subjected to surface hardness testing carried out in accordance with
ISO 6507-1 with measurements taken at three points as shown in Figure 3.
Special jigging shall be used to ensure that the curvature of the link surface does not affect the validity
of the measurements taken. Each result shall meet the requirements of 5.5.4.
6.5 Product
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.