|
UDC 669.14:620.17
IS0
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION
IS0 RECOMMENDATION
R 146
CALIBRATION OF VICKERS HARDNESS TESTING MACHINES
1st EDITION
February 1960
COPYRIGHT RESERVED
The copyright of IS0 Recommendations and IS0 Standards
belongs to IS0 Member Bodies. Reproduction of these
documents, in any country, may be authorized therefore only
by the national standards organization of that country, being
a member of ISO.
For each individual country the only valid standard is the national standard of that country.
Printed in Switzerland
Also issued in French and Russian. Copies to be obtained through the national standards organizations.
---------------------- Page: 1 ----------------------
BRIEF HISTORY
The IS0 Recommendation R 146, Calibration of Vickers Hardness Testing Machines,
was drawn up by Technical Committee ISO/TC 17, Steel, the Secretariat of which is held by
the British Standards Institution (B.S.I.).
Study of this IS0 Recommendation was undertaken by Working Group ISO/TC 17/WG 1,
Methods of Mechanical Testing for Steel, at its meeting, held in London, in November 1954.
Technical Committee ISO/TC 17, at its plenary meeting, held in London, in March 1957,
examined the final draft proposal drawn up by the Working Group. After a number of minor
modifications had been made in it, the decision was reached to submit it by correspondence
L
to the members of the Technical Committee. The results of this consultation showed that
further amendments were needed, and a revised draft incorporating these amendments was
adopted as a Draft IS0 Recommendation.
On 11 July 1958, the Draft IS0 Recommendation (No. 204) was distributed to all the
IS0 Member Bodies and was approved, subject to small modifications, by the following
Member Bodies :
Austria France Norway
Poland
Belgium Germany
Hungary Romania
Bulgaria
Burma India Spain
Chile Israel Sweden
Czechoslovakia Italy Switzerland
United Kingdom
Denmark Japan
Finland New Zealand Yugoslavia
One Member Body opposed the approval of the Draft: U.S.S.R.
The Draft IS0 Recommendation was then submitted by correspondence to the IS0 Council,
L
which decided, in February 1960, to accept it as an IS0 RECOMMENDATION.
-3-
---------------------- Page: 2 ----------------------
ISO/R 146 - 1960 (E)
~ ~ ~~~~ ~~
IS0 Recommendation
R 146 February 1960
CALIBRATION OF VICKERS HARDNESS TESTING MACHINES
1. SCOPE
This IS0 Recommendation applies to the calibration of testing machines for determining Vickers
a,
hardness in accordance with IS0 Recommendation R 81, Vickers Hardness Test .for Steel.
If a machine is also intended for other methods of hardness testing, it should be calibrated for
each method.
2. DIRECT CALIBRATION
Direct calibration iiivolves :
1. Calibration of the load-applying mechanism (see clause 2.1) and verification of the
indenter (see clause 2.2),
which together constitute the standard for the method of test, and
2. Verification of the measuring device (see clause 2.3).
Before calibration is carried out, certain details of the testing machine should be checked *
L
* Before a Vickers hardness testing machine is calibrated, the machine should be examined to ensure that:
(a) The machine is properly set up;
(b) The plunger holding the penetrator is capable of sliding in its guide, under its own weight, but without any
;
appreciable clearance
(c) The indenter-holder is mounted firmly in the plunger;
(4 The load can be applied and removed without shock and in such a manner that the readings are not influenced;
(e) If the measuring device is integral with the machine,
1. the change from loading to measuring does not influence the readings,
2. the method of illumination does not affect the readings,
3. the centre of the indentation is in the centre of the field of view.
-5-
---------------------- Page: 3 ----------------------
ISO/R 146-1960 (E)
2.1 Calibration of the load-applying mechanism
2.1.1 The calibration of the load-applying mechanism at the required loads should be
carried out either directly by mea
...