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UDC 621.882.1 - 472
IS0
FOR STA N DA RD IZATl O N
1 NT ERN AT1 ON AL ORGAN I2 AT1 ON
IS0 RECOMMENDATION
R 273
PART II
CLEARANCE HOLES FOR METRIC BOLTS
42 UP TO AND INCLUDING 150 mm THREAD DIAMETER
1st EDITION
November 1968
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.
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BRIEF HISTORY
IS0 Recommendation U 273. Part II, Clearance holes for metric bolts 42 up to and including
150 mm thread diameter, was drawn up by Technical Committee ISO/TC 2, Bolts, nuts and
accessories, the Secretariat of which is held by the Deutscher Normenausschuss (DNA).
IS0 Recommendation R 273-1962, which is now considered as Part I of ISO/R 273, refers to
clearance holes for metric bolts with thread diameters from 1.6 up to and including 39 mm, in
conformity with IS0 Recommendation R 272-1 961.
IS0 Recommendation R 273, Part il, was prepared to conform with a revision of IS0 Recom-
mendation R 272, published in 1968 and containing additional specifications for hexagon bolts and
nuts with thread diameters from 42 up to and including 150 mm. In conjunction with that revision, a
proposal concerning clearance holes for metric bolts with these diameters was adopted by the
Technical Committee in October, 1966.
In August 1967, this document, intended originally as an addendum to IS0 Recommendation
K 273-1962, was circulated as Draft IS
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