The plating shall be applied over an intermediate coating of nickel or nickel over copper on steel, zinc and zinc-base alloys. Copper and copper base alloys require intermediate coatings. Copper-alloy-basis metal articles on which a nickel undercoat is not used and other basis metal whereon a copper undercoat is employed shall not be used for continuous service at a temperature in excess of C F. Adhesion of the silver plating is adversely affected because of the formation by diffusion of a weak eutectic of silver and copper at the silver-copper interface.
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A number in parentheses indicates the year of last reapproval. It is the responsibility of the user of this standard toestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.
Referenced Documents2. Current edition approved May 1, Published May Originallyapproved in Last previous edition approved in as B — Whennecessary, the significant surfaces shall be indicated on thedrawings of the parts, or by the provisions of suitably markedsamples. Therefore, the coating thickness willhave to exceed the specified value at some points on thesignificant surfaces to ensure that the thickness equals orexceeds the specified value at all points. The average coatingthickness on the article usually will be greater than thatspecified; how much greater is largely determined by the shapeof the article see Practice B and the characteristics of theelectroplating process.
Additionally, the average coating thick-ness on an article will vary from article to article within aproduction lot. If all the articles in a production lot are to meetthe thickness requirement, the average coating thickness of aproduction lot as a whole will be greater than the averagenecessary to ensure that a single article meets requirements.
Grade B, Bright—Electrodeposits obtained by the use ofbrighteners in the electroplating bath. Grade C, Bright—Electrodeposits obtained by mechanicalor chemical polishing of Grade A silver coatings. Grade D, Semibright— Semi-lustrous electrodeposits ob-tained by the use of addition agents in the electroplating bath. Class S—A finish that has had a supplementary tarnishresistant that is, chromate treatment.
Ordering Information5. If it is copper, an undercoatis needed see S1. Coating Requirements6. NOTE 4—Silver deposits may be used to facilitate mechanical opera-tions such as forming and drawing. In these applications, silver is appliedbefore such process steps.
Specification B may be consulted for a list ofpretreatments that are used widely. Nickel underplatings are also appliedfor other reasons. Specification B may be con-sulted for a list of post-treatments that are used widely. The requirementfor uniform color or appearance need not apply for subsequentpassivation or other treatments of the silver.
Such defects that persists in the finish despitethe observance of good metal finishing practices shall not because for rejection. NOTE 5—Coated finishes generally perform better in service when thesubstrate over which they are applied is smooth and free from torn metal,inclusions, pores, and other defects.
It is recommended that the specifi-cations covering the unfinished product provides limits for those defects. A metal finisher often can remove defects by means of special treatmentssuch as grinding, polishing, abrasive blasting, chemical treatments, andelectropolishing. However, these are not normal for the treatment stepspreceding application of the finish. When they are desired, they are thesubject of special agreement between the purchaser and the supplier.
NOTE 6—Some applications may require no separation by any mechani-cal means such as machining or milling through the interface. The articles in the lot shall be classified as conform-ing or nonconforming to each requirement according to thecriteria of the sampling plans in the chosen method.
NOTE 7—Test Method B contains four sampling plans, three for usewith nondestructive test methods; the fourth is for use with destructive testmethods.
This iframe contains the logic required to handle Ajax powered Gravity Forms. For more information on our full line of Silver services please visit our silver plating services page. You can also request a quote or contact a member of our technical sales team for more information. Per 6. Nickel underplatings are also applied for other reasons. Per
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