SIST EN ISO 6508-2:2006
(Main)Metallic materials - Rockwell hardness test - Part 2: Verification and calibration of testing machines (scales A, B, C, D, E, F, G, H, K, N, T) (ISO 6508-2:2005)
Metallic materials - Rockwell hardness test - Part 2: Verification and calibration of testing machines (scales A, B, C, D, E, F, G, H, K, N, T) (ISO 6508-2:2005)
This part of ISO 6508 specifies a method of verification of testing machines for determining Rockwell hardness (scales A, B, C, D, E, F, G, H, K, N, T) in accordance with ISO 6508-1. It specifies a direct method for checking the main functions of the machine operation and an indirect method suitable for the overall checking of the machine. The indirect method may be used on its own for periodic routine checking of the machine in service. If a testing machine is also to be used for other methods of hardness testing, it shall be verified independently for each method. This part of ISO 6508 is applicable to portable hardness testing machines with the exception of requirements in 6.1a) in which the word "relocation" does not apply.
Metallische Werkstoffe - Härteprüfung nach Rockwell - Teil 2: Prüfung und Kalibrierung der Prüfmaschinen (Skalen A, B, C, D, E, F, G, H, K, N, T) (ISO 6508-2:2005)
In diesem Teil von ISO 6508 ist das Verfahren für die Prüfung und Kalibrierung von Härteprüfmaschinen zur Bestimmung der Rockwellhärte (Skalen A, B, C, D, E, F, G, H, K, N, T) nach ISO 6508-1 festgelegt.
Es ist ein direktes Verfahren zur Prüfung von Hauptfunktionen der Maschine und ein indirektes Verfahren, das zur Ermittlung der Funktionsfähigkeit der Maschine geeignet ist, festgelegt. Das indirekte Verfahren kann für die regelmäßige Routineüberprüfung der Maschine beim Anwender angewendet werden.
Wird eine Härteprüfmaschine auch für andere Härteprüfverfahren verwendet, muss sie unabhängig für jedes dieser Verfahren geprüft werden.
Dieser Teil von ISO 6508 ist auch anwendbar auf tragbare Härteprüfmaschinen.
Matériaux métalliques - Essai de dureté Rockwell - Partie 2: Vérification et étalonnage des machines d'essai (échelles A, B, C, D, E, F, G, H, K, N, T) (ISO 6508-2:2005)
L'SO 6508-2:2005 spécifie une méthode de vérification des machines d'essai utilisées pour la détermination de la dureté Rockwell (échelles A, B, C, D, E, F, G, H, K, N, T) conformément à l'ISO 6508-1.
Kovinski materiali – Preskus trdote po Rockwellu – 2. del: Preverjanje in umerjanje naprav za preskušanje (skale A, B, C, D, E, F, G, H, K, N, T) (ISO 6508-2:2005)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 6508-2:2006
01-marec-2006
1DGRPHãþD
SIST EN ISO 6508-2:2000
Kovinski materiali – Preskus trdote po Rockwellu – 2. del: Preverjanje in umerjanje
naprav za preskušanje (skale A, B, C, D, E, F, G, H, K, N, T) (ISO 6508-2:2005)
Metallic materials - Rockwell hardness test - Part 2: Verification and calibration of testing
machines (scales A, B, C, D, E, F, G, H, K, N, T) (ISO 6508-2:2005)
Metallische Werkstoffe - Härteprüfung nach Rockwell - Teil 2: Prüfung und Kalibrierung
der Prüfmaschinen (Skalen A, B, C, D, E, F, G, H, K, N, T) (ISO 6508-2:2005)
Matériaux métalliques - Essai de dureté Rockwell - Partie 2: Vérification et étalonnage
des machines d'essai (échelles A, B, C, D, E, F, G, H, K, N, T) (ISO 6508-2:2005)
Ta slovenski standard je istoveten z: EN ISO 6508-2:2005
ICS:
77.040.10 Mehansko preskušanje kovin Mechanical testing of metals
SIST EN ISO 6508-2:2006 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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EUROPEAN STANDARD
EN ISO 6508-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2005
ICS 77.040.10 Supersedes EN ISO 6508-2:1999
English Version
Metallic materials - Rockwell hardness test - Part 2: Verification
and calibration of testing machines (scales A, B, C, D, E, F, G,
H, K, N, T) (ISO 6508-2:2005)
Matériaux métalliques - Essai de dureté Rockwell - Partie 2: Metallische Werkstoffe - Härteprüfung nach Rockwell - Teil
Vérification et étalonnage des machines d'essai (échelles 2: Prüfung und Kalibrierung der Prüfmaschinen (Skalen A,
A, B, C, D, E, F, G, H, K, N, T) (ISO 6508-2:2005) B, C, D, E, F, G, H, K, N, T) (ISO 6508-2:2005)
This European Standard was approved by CEN on 14 December 2005.
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 Central Secretariat 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 Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
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EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 6508-2:2005: E
worldwide for CEN national Members.
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EN ISO 6508-2:2005 (E)
Foreword
This document (EN ISO 6508-2:2005) has been prepared by Technical Committee ISO/TC 164
"Mechanical testing of metals" in collaboration with Technical Committee ECISS/TC 1 "Steel -
Mechanical testing", the secretariat of which is held by AFNOR.
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 June 2006, and conflicting national
standards shall be withdrawn at the latest by June 2006.
This document supersedes EN ISO 6508-2:1999.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of
the following countries are bound to implement this European Standard: Austria, Belgium,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary,
Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
Endorsement notice
The text of ISO 6508-2:2005 has been approved by CEN as EN ISO 6508-2:2005 without any
modifications.
2
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INTERNATIONAL ISO
STANDARD 6508-2
Second edition
2005-12-15
Metallic materials — Rockwell hardness
test —
Part 2:
Verification and calibration of testing
machines (scales A, B, C, D, E, F, G, H, K,
N, T)
Matériaux métalliques — Essai de dureté Rockwell —
Partie 2: Vérification et étalonnage des machines d'essai (échelles A, B,
C, D, E, F, G, H, K, N, T)
Reference number
ISO 6508-2:2005(E)
©
ISO 2005
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ISO 6508-2:2005(E)
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ii © ISO 2005 – All rights reserved
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ISO 6508-2:2005(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 General conditions . 1
4 Direct verification. 2
5 Indirect verification. 5
6 Intervals between verifications . 8
7 Verification report/calibration certificate . 8
Annex A (normative) Repeatability of testing machines. 9
Annex B (informative) Uncertainty of measurement of the calibration results of the hardness
testing machine. 11
Bibliography . 18
© ISO 2005 – All rights reserved iii
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ISO 6508-2:2005(E)
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 6508-2 was prepared by Technical Committee ISO/TC 164, Mechanical testing of metals, Subcommittee
SC 3, Hardness testing.
This second edition cancels and replaces the first edition (ISO 6508-2:1999), which has been technically
revised.
ISO 6508 consists of the following parts, under the general title Metallic materials — Rockwell hardness test:
— Part 1: Test method (scales A, B, C, D, E, F, G, H, K, N, T)
— Part 2: Verification and calibration of testing machines (scales A, B, C, D, E, F, G, H, K, N, T)
— Part 3: Calibration of reference blocks (scales A, B, C, D, E, F, G, H, K, N, T)
iv © ISO 2005 – All rights reserved
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ISO 6508-2:2005(E)
Introduction
Attention is drawn to the fact that, in this part of ISO 6508, the use of hardmetal for ball indenters is
considered to be the standard type of Rockwell indenter ball. Steel indenter balls may be continued to be used
if specified in a product specification, or by special agreement.
© ISO 2005 – All rights reserved v
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INTERNATIONAL STANDARD ISO 6508-2:2005(E)
Metallic materials — Rockwell hardness test —
Part 2:
Verification and calibration of testing machines (scales A, B, C,
D, E, F, G, H, K, N, T)
1 Scope
This part of ISO 6508 specifies a method of verification of testing machines for determining Rockwell
hardness (scales A, B, C, D, E, F, G, H, K, N, T) in accordance with ISO 6508-1.
It specifies a direct method for checking the main functions of the machine operation and an indirect method
suitable for the overall checking of the machine. The indirect method may be used on its own for periodic
routine checking of the machine in service.
If a testing machine is also to be used for other methods of hardness testing, it shall be verified independently
for each method.
This part of ISO 6508 is applicable to portable hardness testing machines.
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 376:2004, Metallic materials — Calibration of force-proving instruments used for verification of uniaxial
testing machines
ISO 6507-1, Metallic materials — Vickers hardness test — Part 1: Test method
ISO 6508-1, Metallic materials — Rockwell hardness test — Part 1: Test method (scales A, B, C, D, E, F, G, H,
K, N, T)
ISO 6508-3:2005, Metallic materials — Rockwell hardness test — Part 3: Calibration of reference blocks
(scales A, B, C, D, E, F, G, H, K, N, T)
3 General conditions
Before a Rockwell hardness testing machine is verified, the machine shall be checked to ensure that it is
properly set up in accordance with the manufacturer's instructions:
Especially it should be checked that:
a) the plunger holding the indenter is capable of sliding in its guide;
© ISO 2005 – All rights reserved 1
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ISO 6508-2:2005(E)
b) the indenter-holder is firmly mounted in the plunger;
c) the test force can be applied and removed without shock or vibration and in such a manner that the
readings are not influenced.
It shall be checked that the readings are not affected either by movements of the test piece or by deformation
of the frame. When a device is supplied, which locks the test piece against the upper part of the frame, the
locking force shall exceed the total test force. The influence of deformations may be checked by using a
plunger with a spherical tip (diameter of at least 10 mm), instead of the indenter, bearing against the anvil
through a spacer and using the locking device when it is supplied. The material of the plunger and of the
spacer have a hardness of at least 60 HRC. The readings of the measuring system (with preliminary force
applied) before application and after removal of the additional force shall not differ by more than 1,5 Rockwell
units (without locking equipment) and 0,5 Rockwell units (with locking equipment).
4 Direct verification
4.1 General
4.1.1 Direct verification should be carried out at a temperature of (23 ± 5) °C. If the verification is made
outside of this temperature range, this shall be reported in the verification report.
4.1.2 The instruments used for verification and calibration shall be traceable to national standards.
4.1.3 Direct verification involves:
a) calibration of the test force;
b) verification of the indenter;
c) calibration of the depth-measuring system;
d) verification of the testing cycle.
4.2 Calibration of the test force
4.2.1 The preliminary test force F (see 4.2.4) and each total test force F used (see 4.2.5) shall be
0
measured, and, whenever applicable, this shall be done at not less than three positions of the plunger spaced
throughout its range of movement during testing. The preliminary test force shall be held for at least 2 s.
4.2.2 Three readings shall be taken for each force at each position of the plunger. Immediately before each
reading is taken, the plunger shall be moved in the same direction as during testing.
4.2.3 The forces shall be measured by one of the following two methods:
⎯ by means of a force proving device in accordance with ISO 376:2004, class 1, or
⎯ by balancing against a force, accurate to ± 0,2 %, applied by means of calibrated masses or by another
method having the same accuracy.
4.2.4 The tolerance on the preliminary test force F (before application and after removal of the additional
0
test force F ) shall be ± 2,0 %.
1
4.2.5 The tolerance on the total test force F shall be ± 1,0 %. Each individual value of F shall be within this
tolerance.
2 © ISO 2005 – All rights reserved
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ISO 6508-2:2005(E)
4.3 Verification of the indenter
4.3.1 Diamond cone indenter (scales A, C, D, N)
To verify the reliable performance of the conical indenter in conformance with this part of ISO 6508, a direct
and an indirect verification shall be carried out.
4.3.1.1 Direct verification
4.3.1.1.1 The surfaces of the diamond cone and spherical tip shall be polished for a penetration depth of
0,3 mm and shall blend in a truly tangential manner. Both surfaces shall be free from surface defects.
4.3.1.1.2 The verification of the shape of the indenter can be made by direct measurement or by
measurement of its projection on a screen. The verification shall be made at not less than four equally spaced
sections.
4.3.1.1.3 The diamond cone shall have an included angle of (120 ± 0,35)°.
Deviations from straightness of the generatrix of the diamond cone, adjacent to the blend, shall not exceed
0,002 mm over a minimum length of 0,4 mm.
4.3.1.1.4 The angle between the axis of the diamond cone and the axis of the indenter-holder (normal to
the seating surface) shall not exceed 0,5°.
4.3.1.1.5 The tip of the indenter shall be spherical. Its radius shall be determined from single values,
measured in the axial section planes defined in 4.3.1.1.2. The distance between the concentric circles shall be
no more than 0,004 mm. Each single value shall be within (0,2 ± 0,015) mm. The mean value out of at least
four single values shall be within (0,2 ± 0,01) mm.
NOTE 1 The radius can be obtained by determining the intersection of two segments of the concentric circles.
NOTE 2 The single value is the mean value of the two radii of the concentric circles.
Measurement with a collimator device is also available. In this case, the measurements should be carried out
at least in four central angles and the central angle of 120° must be included.
4.3.1.2 Indirect verification
The hardness values given by the testing machine depend not only on the dimensions given in 4.3.1.1.3 and
4.3.1.1.5, but also on the surface roughness and the position of the crystallographic axes of the diamond, and
the seating of the diamond in its holder.
To examine this influence, the indirect verification of the indenter shall be performed on four reference blocks
which shall be calibrated for the hardness levels given in Table 1 or on blocks giving equivalent total depths of
indentation.
Table 1 — Hardness levels for different scales
Scale Hardness Ranges
HRC 23 20 to 26
HRC 55 52 to 58
HR45N 43 40 to 46
HR15N 91 88 to 94
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ISO 6508-2:2005(E)
For each block, the mean hardness value of three indentations made using the indenter to be verified shall not
differ from the mean hardness value of the three indentations obtained with the indenter, calibrated in
accordance with 4.5 of ISO 6508-3:2005 by more than ± 0,8 Rockwell units. The indentations made with the
indenter to be verified and with the above-mentioned indenter should be adjacent.
NOTE This can be performed with a calibration machine in accordance with the procedure described in Clause 5 of
ISO 6508-3:2005.
The hardness testing machines used for this indirect verification shall comply with the following tolerances for
the test forces:
F : ± 1,0 %
0
F : ± 0,5 %
The test shall be carried out in accordance with ISO 6508-1.
4.3.2 Ball indenter (scales B, E, F, G, H, K, T)
4.3.2.1 For the purpose of verifying the size and the hardness of the balls, one sample selected at
random from a batch shall be tested. The balls verified for hardness shall be discarded.
4.3.2.2 The balls shall be polished and free from surface defects.
4.3.2.3 The user shall either measure the balls to ensure that they meet the following requirements, or
shall obtain balls from a supplier certifying that the following conditions are met.
4.3.2.3.1 The diameter, measured at no less than three positions, shall not differ from the nominal diameter
by more than the tolerance given in Table 2.
Table 2 — Tolerances for the different ball diameters
Ball diameter Tolerance
Rockwell hardness scale
mm mm
B 1,587 5 ± 0,003 5
F 1,587 5 ± 0,003 5
G 1,587 5 ± 0,003 5
T 1,587 5 ± 0,003 5
E 3,175 ± 0,004
H 3,175 ± 0,004
K 3,175 ± 0,004
4.3.2.3.2 The characteristics of the hardmetal balls shall be as follows:
⎯ hardness: the hardness shall be no less than 1 500 HV, when determined using a test force of at least
4,903 N in accordance with ISO 6507-1. The hardmetal ball may be tested directly on this spherical
surface or by sectioning the ball and testing on the ball interior. An example for HV 10 is given in Table 3.
3
⎯ density: ρ = (14,8 ± 0,2) g/cm .
NOTE The following chemical composition is recommended:
— tungsten carbide (WC) balance
— total other carbides 2,0 %
— cobalt (Co) 5,0 % to 7,0 %
4 © ISO 2005 –
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