INTERNATIONAL
STANDARD 4532
First edi tion
1991-12-01
Vitreous and porcelain enamels -
Determination
of the resistance of enamelled
articles to impact - Pistol test
Emaux vifrifi& - Determination de la rksistance au choc des pikes
6maiMes - Essai au
ISO 4532:1991(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. Esch 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, govern-
mental 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.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an Inter-
national Standard requires approval by at least 75 % of the member
bodies casting a vote. iTeh STANDARD PREVIEW
International Standard (standards.iteh.ai)
ISO 4532 was prepared by Technical Committee
ISO/TC 107, Metallic and other inorganbc coafings, Sub-Committee SC
6, Vitreous and porcelain enamels. ISO 4532:1991
https://standards.iteh.ai/catalog/standards/sist/48321ee5-b08f-488f-b041-
lt is based on a test method developed by a committee of the VDEfa. The
VDEfa Technical Report No. 4 [l] describes 10202c4682f8/iso-4532-1991
the development of the
Pistol test and gives comprehensive information on numerous Pistol
tests carried out on different shapes of test specimens.
Annexes A and B of this International Standard are for information only.
6 ISO 1991
All rights reserved. No part of this publication may be reproduced or utilized in any form
or by any means, electronie or mechanical, including photocopying and microfilm, without
Permission in writing from the publisher.
International Organization for Standardization
Case Postale 56 l CH-121 1 Geneve 20 * Switzerland
Printed in Switzerland
ii
INTERNATIONAL STANDARD ISO 4532:1991 (E)
Vitreous and porcelain enamels - Determination of the
resistance of enamelled articles to impact - Pistol test
1 Scope 4 Apparatus
This International Standard specifies a test method
for determining the resistance of enamelled articles
to impact.
The method is used as a factory production control The test apparatus (see figure 1) consists of a strik-
test. ing bolt with a 5 mm steel ball tip which is shot once
against the surface under test by means of a press-
NOTE 1 The Pistol test is not intended to be used for ure spring (100 mm long, unloaded). The spring load
iTeh STANDARD PREVIEW
testing the adhesion of the enamel. tan be continuously adjusted from 0 to 90 N by the
power-adjusting sleeve.
2 Normative reference
(standards.iteh.ai) NOTE 2 The newton-metre scale provided on the out-
side of the apparatus shall only be used as a guide be-
The following Standard contains provisions which,
ISO 4532:1991
Cause a non-linear scale tan lead 20 significant errors.
through reference in thishttps://standards.iteh.ai/catalog/standards/sist/48321ee5-b08f-488f-b041-
text, constitute provisions
of this International Standard. At the time10202c4682f8/iso-4532-1991
of publi- The pressure spring is loaded by means of a clamp.
cation, the edition indicated was valid. All Standards The spring constant is 20 N/cm + 0,5 N/cm. When
are subject to revision, and Parties to agreements the spring is loaded, it is kept stat!nary by a holder
based on this International Standard are encour- on the striking bolt and released by the trigger for
aged to investigate the possibility of applying the striking. For testing, a tripod tan be fixed at the front
most recent edition of the Standard indicated below. of the apparatus in Order to keep the apparatus
Members of IEC and ISO maintain registers of cur- vet-tical against the test surface. The front of the tool
rently valid International Standards. is convex-shaped for testing concave articles. For
testing articles with small radii, it is supplied with a
ISO 2746:1973, Vitreous and porcelain enamels - Cross-groove. In the range of application of the
Enameled artkIes for Service under highly corrosive apparatus, the error in reading shall not be greater
conditions - High voltage test. than 3 %.
3 Principle See annex A for the calibration and determination
of the Zero Point of the apparatus.
Shooting of a ball-tipped striking bolt of an appar-
atus operated by adjustable spring tension, against
the surface of the test specimen. Evaluation of the
Point of impact.
The load applied to the striking bolt. which with one
blow produces visible darnage to the enamel, is in-
versely proportional to the sensitivity of the
enamelled article to impact.
ISO 4532:1991(E)
Dimensions in millimetres
Layer of soft rubber
Figure 1 - Test apparatus (The pressure spring is shown loaded)
5 Test specimens The first visible sign of darnage of enamel at the
Point of impact shall be used as a criterion of the
The enamelled articles are the test specimens. The impact sensitivity of the enamelled article, for ex-
sampling of the test specimens and their number ample cracking, powdering Off, spalling and
shall be agreed upon between the supplier and the chipping. The mark of the striking bolt shall not be
customer. If no agreement had been made, test at considered as sign of darnage.
least two test specimens.
After the Pistol test, it is permitted to rub the test
specimen with an alcoholic dye Solution, an ink or
iTeh STANDARD PREVIEW a similar colouring Solution, to make the darnage
6 Procedure more easily visible.
(standards.iteh.ai)
In addition, it tan be advantageous to use the high-
The test specimens shall be tested in conditions
identical to those used in practice. For testing, the ISO 4532:1991 voltage test (according to ISO 2746) for certain arti-
cles, especially those used under highly corrosive
apparatus may be fixed in a https://standards.iteh.ai/catalog/standards/sist/48321ee5-b08f-488f-b041-
strong support and the
test specimens fixed with the surfaces to be tested conditions.
10202c4682f8/iso-4532-1991
against the front of the apparatus.
NOTE 3 Test results tan only be compared if
Carry out the Pistol test at various places with in-
creasing loads. a) the test specimens are similar, especially considering
the thickness of the basis metal and of the enamel
In a preliminary test, starting with a load of 10 N and coat;
increasing by IO N each time, establish the integer
of 10 N at which the enamel is not visibly damaged. b) the same kind of support was used;
From this value onwards, increase the spring load
c) the Pistol tests were applied to similar Points on the
by 2 N each time until the first visible darnage is
test specimens.
noticed (see clause 7).
The distance between two Points of impact, or the
distance between a Point of impact and a sign of
darnage on the enamel, shall be at least 20 mm. 8 Test report
The park of the enamelled articles which shall be
The test report shall include the following infor-
submitted to the Pistol tests and their conditions of
mation:
support shall be agreed upon for each case.
Carry out at least five Pistol tests. a) a reference to this International Standard;
b) a description of the articles tested (especially
their dimensions and mass, and if possible a
7 Expression of results Sketch; or also the thickness of the basis metal
and of the enamel coat);
After each Pistol test, observe the Point of impact
from a distance of 250 mm by normal sight and note c) the number of specimens tested;
the type of darnage. The final valuation shall be
made after 24 h. d) the type of support used;
2
ISO 4532:1991(E)
the Position of the Points of impact on the article l-9 the appearance of the damaged places, if
(for example in the case of Pots: rim, bottom, in- necessary with Photographs;
side or outside);
i) whether the high-voltage test was used and, id
the number of Pistol tests per test specimen; so, the voltage applied.
the spri ng load used, in n ewtons, roun ded to the
nearest 2 N, necessary to darnage the enamel;
iTeh STANDARD PREVIEW
(standards.iteh.ai)
ISO 4532:1991
https://standards.iteh.ai/catalog/standards/sist/48321ee5-b08f-488f-b041-
10202c4682f8/iso-4532-1991
ISO 4532:1991 (E)
Annex A
(informative)
Calibration and determination of the Zero Point of the apparatus
A.1 Calibration
Table A.l - Values obtained for two different
Clamp the striking bolt with its barrel in a vertical apparatuses when tested according to A.l
Position in a support so that the bolt tan be loaded
Values in newtons
and unloaded.
Apparatus reading
The loading of the striking bolt is effected by dis- Load 1
mantling the clamp, thus freeing a hole into which applied
Apparatus No. 1 Apparatus No. 2
a rod with a length of about 15 cm tan be inserted, I
corresponding to pre-defined striking bolt load.
17,5
If the apparatus is supplied with a bolt on the back 23,0
of the apparatus, dismantling is not necessary as 27,5
the calibration weights tan be fixed there.
57,5
Submit the striking bolt to a load of 10 N. Determine,
by reading the scale, the Position in which the load
iTeh STANDARD
is neutralized by checking that the striking bolt is
AccordingPREVIEW
to figureA.1, the Zero deviation of appar-
atus No. 1 is 3 N, that of apparatus No. 2 is 7 N.
just unloaded. Repeat this procedure with increas-
ing loads. (standards.iteh.ai)
Plot a graph of the readings adjusted as a function 60
ISO 4532:1991
sf the weight of the rod against the loads. Read the
Zero-Point
https://standards.iteh.ai/catalog/standards/sist/48321ee5-b08f-488f-b041-
deviation from the graph (see examples
in A.2).
10202c4682f8/iso-4532-1991
The spring constant is correct when the graph
makes an angle of 45” with the axes. If this is not the
case, the apparatus is not suitably calibrated and a
correction shall be made using the graph.
A.2 Examples for the determinatian of the
zero Point of two different aparatuses
The values given in table A.l were obtained for two
different apparatuses, when tested according to
A.1.
Y Scale graduation of striking holt, in newtons -
Figure A.1 - Graph for the determination of the
Zero Point of two different apparatuses
ISO 4532:1991(E)
Annex B
(informative)
Bibliography
[l] Fachausschuß-Bericht Nr. 4 des Vereins Brunke Garrels, Hamburg, 1958. [Available
Deutscher Emailfachleute e.V. Prüfung von from: Verlag des Vereins Deutscher
Email: Schlagversuch. [Technical Report No. 4 Emailfachleute e.V., Zehlendorfer Straße 24,
of the Society of German Enamel Specialists: D - 5800 Hagen 1.1
Testing of enamel - Piste/ test]. Publisher
iTeh STANDARD PREVIEW
(standards.iteh.ai)
ISO 4532:1991
https://standards.iteh.ai/catalog/standards/sist/48321ee5-b08f-488f-b041-
10202c4682f8/iso-4532-1991
ISO 4532:1991 (E)
iTeh STANDARD PREVIEW
(standards.iteh.ai)
ISO 4532:1991
https://standards.iteh.ai/catalog/standards/sist/48321ee5-b08f-488f-b041-
10202c4682f8/iso-4532-1991
UDC 666.293:620.178.7
Descriptors: coatings, non metallic coatings, vitreous enamels, porcelain enamels, tests, impact tests.
Price based on 5 pages
