AWS A5.19-92:2015 pdf download.Specification for Magnesium Alloy Welding Electrodes and Rods
5. Units of Measure and Rounding-Off Procedure
5.1 U.S. customary units are the standard units of mea-sure in this specification. The SI units are given as equivalent values to the U.S. customary units. The stan-dard sizes and dimensions in the two systems are not identical, and for this reason, conversion from a standard size or dimension in one system will not always coincide with a standard size or dimension in the other. Suitable conversions, encompassing standard sizes of both, can be made, however, if appropriate tolerances are applied in each case.
5.2 For the purpose ofdeterminingconformance with this specification, an observed or calculated value shall be rounded to the“nearest unit" in the last right-hand place of figures used in expressing the limiting value in accord-ance with the rounding-off method given in ASTM E29,Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications.
6. Summary ofTests
The tests required for each classification are specified in Table 2. The purpose of these tests is to determine the chemical composition of the filler metal, soundness of the weld metal produced by gas metal arc welding, and the deposition characteristics of welding rods. The base metal fot the weld test assemblies, the welding and testing procedure to be employed, and the results required are given in Sections 8 through 11.
7. Retest
If the results of any test fail to meet the requirement, that test shall be repeated twice. The results of both retests shall meet the requirement. Material for retest may be taken from the original test sample or from one or two new samples. For chemical analysis, retest need be only for those specific elements that failed to meet the test requirement.
8.2 Usability tests shall be made using electrodes and welding rods of each size. A filler metal that meets the requirements of the radiographic soundness test, when tested as an electrode, may also be classified as a welding rod without being subjected to the bead-on-plate test required for a welding rod. A filler metal that meets the bead-on-plate weld test requirements, when tested as a welding rod, shall also be tested as an electrode and meet the requirements of the radiographic soundness test in order to be classified as an electrode.
8.3 Groove Weld for Soundness and Usability of Electrodes
8.3.1 A test assembly shall be prepared and welded, as specified in Figure 1 and 8.3.2 through 8.3.4, using base metal of the appropriate type specified in Table 3. Testing of this assembly shall be as specified in Section 10,Radiographic Test.
8.3.2 Welding of the test assembly shall be done using the gas metal arc welding process with techniques and procedures specified by the manufacturer as to the condi-tions not covered herein.
8.3.3 Dimensions of the groove weld joint and the welding position shall be as specified in Figure 1 for the electrode diameter being tested. The backing material shall be of the same type as the base metal.AWS A5.19-92 pdf download.