ISO 725:2009 pdf free download – ISO inch screw threads一Basic dimensions.
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 725 was prepared by Technical Committee ISOITC 1, Screw threads.
This second edition results from the reinstatement of ISO 725:1978, which was withdrawn in 2000 and with which it is technically identical.
This International Standard specifies the basic dimensions, in inches, of ISO inch screw threads in accordance with ISO 263. The values refer to the basic profile in accordance with ISO 68-2,
2 Symbols
basic major diameter of internal thread (nominal diameter)
basic major diameter of external thread (nominal diameter)
basic pitch diameter of intema thread
basic pitch diameter of external thread
basic minor diameter of internal thread
d1 basic minor diameter of external thread
H height of fundamental triangle
n number of threads per inch (25,4 mm).