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Ref. No.: ISO/R 50 - 1957 (E)
IS0
RDl ZATl O N
INTERN AT ONAL ORGANIZATION FOR ST DA
-:
IS0 RECOMMENDATION
R 50
STEEL SOCKETS
SCREWED IN ACCORDANCE WITH IS0 RECOMMENDATION R 7
MINIMUM LENGTHS
lSt EDITION
July 1957
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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
The IS0 Recommendation R 50, Steel Sockets, Screwed in accordance with
IS0 Recommendation R 7 - Minimum Lengths, was prepared by Technical
Committee ISO/TC 5, Pipes and Fittings, the Secretariat of which is held by
the Association Suisse de Normalisation (SNV).
At its second plenary meeting held in Milan, in April 1952, the Tech-
nical Committee assigned the study of steel sockets to its Sub-Committee
ISO/TC 5/SC 5, Fittings (other than Cast Iron). At the meeting of the Sub-
committee in London, in September 1952, consideration was given to the
of the minimum lengths of corresponding steel sockets and
standardization
malleable cast iron sockets in conformity with the formula:
a = 2L + np
where L = length of useful thread on n = number of turns
pipe end in accordance with of thread
IS0 Recommendation R 7 p = pitch of thread
As however the views were very divergent, the Sub-Committee decided in Paris,
in September 1953, to deal separately with steel sockets and malleable cast
iron sockets.
The whole question was re-examined in Brussels, in May 1954, at the request
of the French Member Body, which proposed a value of n (number of turns of
thread) = 2. This proposal was adopted by a working group of the Sub-
Committee which met in Zurich, in July 1954, and was thereafter confirmed
by correspondence by all the members of the Sub-Committee. Following a
...