BS EN ISO 6848:2015 pdf free

BS EN ISO 6848:2015 pdf free.Arc welding and cutting一Nonconsumable tungsten electrodes – Classification.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 80000-1:2009 Quantities and units – – Part 1: General
3 Classification
Classification of a tungsten electrode is based upon its chemical composition.
4 Symbols and requirements
4.1 Symbol for the product/process
The symbol for gas shielded tungsten arc processes is the letter W.
4.2 Symbol for the chemical composition
The symbol for the chemical composition of the tungsten electrode is the chemical symbol[s) for the principal oxide additive[s) followed by digits indicating the nominal mass percent of the oxide additive multiplied by 10. If there is no additive, the symbol is the letter P. Table 1 lists the composition requirements for the various classifications.
5 Chemical analysis
Chemical analysis shall be performed on specimens of the electrode being classified. Any analytical technique may be used but, in cases of dispute, reference shall be made to established published methods.
Retests
If any test fails to meet the requirement, that test shall be repeated twice. The results of both retests shall meet the requirements. Specimens for retesting may be taken from the original test specimen or from a new test specimen. For chemical analysis, retests need only be 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 procedures were not followed in preparing the test specimen 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.
7 Marking
Tungsten electrodes 50mm in length and above, as manufactured, shall be marked on the basis of theirchemical composition, with one or more colour rings near one end of the electrode in accordance with Table 1.
The width of the colour rings shall be at least 3 mm. Alternatively, tungsten electrodes may have their classification symbols marked on the surface of the electrode near at least one end of the electrode.
For tungsten electrodes shorter than 50 mm in length, as manufactured, packaging shall be marked in accordance with Clause 11.BS EN ISO 6848 pdf download.