ASTM B972-10 (2020) pdf free.Standard Specification for Nickel-Coated Braid and Ribbon Flat Copper Wire Intendedfor use in Electronic Application.
Whether the nickel is applied by electroplating or bymechanical cladding,coatings less than 50 uin.(0.00005 in.) in thicknesswill not pass the“Continuity of Coating”test.
In general, tested values of tensile strength are increased andtested values of elongation are reduced with increase of speed of themoving head of the testing machine in the tension testing of copper wire.In the case of tests on soft or annealed copper wire, however, the effectsof speed of testing are not pronounced.Tests of soft wire made at speedsof moving head,which under no-load conditions are not greater than 12in./min,do not alter the final results of tensile strength and elongationdeterminations to any practical extent.Consideration should be given to toxicity andflammability when selecting solvent cleaners.
It is important that the polysulfide solution be of propercomposition and strength at the time of test.A solution that is not saturatedwith sulfur or that has been made from decomposed sodium sulfidecrystals may give a false indication of failure. Therefore, the requirementthat the solution be tested by observing its blackening effect on a brightcopper wire is significant.Significant also is the requirement that the solution be saturated with sulfur by allowing the solution to stand at least 24 h after preparation.Attention is called also to the necessity for the useof sodium sulfide that has not deteriorated through exposure to air; and ifexposure has occurred,the crystals should be tested for purity.The“Standard Reagents Tests” of the American Chemical Society are useful inthis connection.
Cumulative results secured on the product of a singlemanufacturer，indicating continued conformance to the criteria,arenecessary to ensure an over-all product meeting the requirements of thisspecification. The sample sizes and conformance criteria given for thevarious characteristics are applicable only to lots produced under theseconditions.ASTM B972 pdf download.