AWS A5.16-A5.16M:2013 pdf download.Specification for Titanium and Titanium-Alloy Welding Electrodes and Rods
4.2 Symbol for the Chemical Composition
The numerical symbols or A WS Classification in Table I indicates the chemical composition of the solid wire or rod,determined under conditions given in Clause 6. The first two digits indicate the alloy group. See Annex A for an expla-nation of the numerical symbols. The second column (A Ws A5. 16/A5.16M Classification) is for reference to previous revisions of this specification.
4.3 Rounding-Off Procedure
For the purpose of determining compliance with the requirements of this standard, the actual test values obtained shall be subjected to the rounding-off rules of ASTM E29, Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications or Rule A in Clause B.3 of ISO 80000- -1:2009 (the results are the same). If the measured values are obtained by equipment calibrated in units other than those of this standard, the measured values shall be converted to the units of this standard before rounding-off. If an average value is to be compared to the require-ments of this standard, rounding off shall be done only after calculating the average. In the case where the testing stan-dard cited in the normative references of this standard contains instructions for rounding-off that confict with the instructions of this standard, the rounding-off requirements of the testing standard shall apply. The rounded-off results shall fulfll the requirements of the appropriate table for the classification under test.
7. Retest
If any test fails to meet the requirement, that test shall be repeated twice. The results of both retests shall meet the require-ment. Specimens for the retest may be taken from the original test sample or from a new test sample. For chemical analy-sis, retests need be only for those specific elements that failed to meet their test requirement. If the results of one or both retests fail to meet the requirement, the material under test shall be considered as not meeting the requirements of this specification for that classification.
In the event that, during preparation or after completion of any test, it is clearly determined that prescribed or proper pro-cedures were not followed in preparing the weld test sample or test specimen(s), or in conducting the tests, the test shall be considered invalid, without regard to whether the test was actually completed, or whether the test results met, or failed to meet, the requirement. That test shall be repeated, following proper prescribed procedures. In this case, the requirement for doubling the number of test specimens does not apply.AWS A5.16-A5.16M pdf download.