SD-2 Dod Acquisitions Buying Commercial Items And Nondevelopmental ItemsThis document offers guidance on acquisitions involving all types of commercial and nondevelopmental items: systems, subsystems, assemblies, parts, and items of supply. Commercial services are also addressed.This document does not present a “cookbook” approach to the acquisition of commercial and nondevelopmental items; such an approach could not accommodate the vast array of potential applications. It does offer lessons learned and things to consider when participating on an integrated product team.

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depend on commercial manufacturers as their sources for electronic components. Manufacturers design and produce electronic components primarily for the commercial market, and those products are lead free. Producing the same product, but using lead, for the defense and aero- space industries would not be economical, because the defense and aerospace requirement for electronic components accounts for less than 1 percent of the electronic components market. Few, if any, can afford to operate two independent manufacturing lines for the same product, one without lead and one containing lead.The end result is that many key components and as- semblies used in aerospace systems are now available only in their lead-free forms.

Even when the defense and aerospace industries can obtain electronic components with lead solder and finishes, they risk mistakenly using lead-free parts in applications requiring high-reli- ability performance unless they implement practices that will mitigate the risk.

Risk Mitigation Strategies

It is essential to understand from the outset whether an application needs RoHS-compliant (lead-free) components or whether it needs components containing lead. RoHS-compliant components should be used in all applications except those requiring high reliability; this practice will preclude penalties associated with noncompliance. On the other hand, if a mili- tary or aerospace application requires high reliability, then only components with traditional tin-lead solder (63 percent tin and 37 percent lead) and lead finishes should be used. Below are a few best practices that may help to avoid potential issues related to leaded versus lead- free components:

•  Ensure that suppliers fully understand the issues of using leaded versus lead-free compo- nents.

•  Verify that suppliers use different part numbers for leaded and lead-free components that are otherwise identical. If different part numbers are not issued, it is difficult to distinguish lead-free parts from leaded parts.This is also an issue when components are returned or when they are recycled.

•  Whenever possible, buy from trusted sources. Avoid unknown sources offering question- able products at a low price.

•  Seek components that have a clear pedigree to verify whether components are lead free or not.

•  Upon receipt of the components, verify that they are truly RoHS compliant or contain lead, whichever is needed to meet the requirements. Sample and test parts whenever a pedigree for the part is not available. An x-ray process can tell if there is lead in the part, without destroying the part, but it cannot detect all of the hazardous materials listed in the RoHS directive.The most certain way of testing a part involves destroying it to get a complete chemical breakdown.

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