IS 193 : 2024/ISO 9453 : 2020 Soft Solder Alloys - Chemical Compositions and Forms - Specification
NATIONAL FOREWORD
This Indian Standard (Sixth Revision) which is identical to ISO 9453 : 2020 'Soft solder alloys -Chemical compositions and forms' issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on the recommendation of the Ores and Feed Stock for Non-Ferrous (Excluding Aluminium and Copper) Industry, their Metals/ Alloys and Products Sectional Committee and approval of the Metallurgical Engineering Division Council. The standard was first published in 1950 as a tentative standard which covered at total of 8 grades of soft solders; three grades of tin-lead-antimony (Antimonial Solders) and five grades of tin-lead (Non-Antimonial Solders) soft solders. The standard was subsequently revised in 1956, 1966, 1977, 1982 and 2000. The first revision of the standard was published in 1956, in which an additional grade tin-lead-antimony was added namely Sn32 Sb. Apart from providing the additional grade of soft solder, the first revision of the standard covered requirements with regard to manufacture, sampling, chemical analysis and supply. Subsequently, an amendment to first revision was published in 1960, which further included five new grades of soft solders; two grades of tin-lead-antimony and three grades of tin-lead soft solders. The amendment issued, further incorporated four new alloys of soft solders suitable for high temperature services as an Annex B. The second revision of the standard included one more grade of soft solder, Sn 38 (Tin-Lead Soft Solder), to cover the soldering of tin containers. Subsequently, after the publication of the second revision of the standard, an amendment was issued, which modified the impurity content of Iron in Grade Sn 45 and Silver contents in Sn5Ag1.5, Sn5Ag1 and Sn1Ag1.5. The third revision of the standard published in 1977 and in this revision, the table on chemical composition was modified and the limits of three impurities arsenic,iron and copper were specified while other impurities where left to the discretion of manufacturer sothat their presence in such amounts won't affect the properties of solders. The third revision of the standard also deleted the grade Sn 38 and replaced the grade Sn 19 by Sn 20; tolerances on tin contents of various grades had also been specified. The fourth revision published in 1982 and in that revision, a new Table 3 specifying the chemical composition of two new grades Sn 38 and Sn 2 of soft solders for special application were included. The fifth revision of the standard published in 2000, included a new grade Sn 15 in Table 1 of the standard which is intended for use in lamp manufacture, replacing the more expensive grades containing higher tin content. Subsequent to the publication of the fifth revision of the standard, an Amendment No. 1 was issued in 2009 to modify the antimony percent of Grade Sn65, Sn 60 and lead percent of grade Sn95Sb5.
In this revision of this standard has been undertaken to align with ISO 9453 : 2020 under dualnumbering system to harmonize it with the latest developments that have taken place at international level as ISO 9453 : 2020 is most widely accepted standard in the Indian solder industry and at the international platform and covers a large number of grades of solders; both lead and lead free solder alloys. Further in this revision, the title of the standard has been changed to 'Soft solder alloys - Chemical compositions and forms - Specification' from 'Soft solder - Specification'.
The text of ISO standard has been approved as suitable for publication as in Indian Standard without deviations. Certain terminologies and conventions are, however, not identical with those used inIndian Standard. Attention is especially drawn to the following:
a)Wherever the words 'International Standard' appear referring to this standard, it should be readas 'Indian Standard'; and
b)Comma (,) has been used as a decimal marker while in Indian Standards the current practiceis to use a point (.) as the decimal marker.