Page 43 - ConnectorSupplier.com 2019 Mil/Aero eBook

Contacts can be electroplated with various materials, depending on an application’s performance requirements and cost constraints.
The M39029 specification historically required 0.000050” of gold plating over the entire outer surface of the contact, but now allows for selective gold plating. Selective plating offers significant cost savings for M39029 connectors and can also make thicker gold plating, which increases the number of mating cycles by offering improving wear and tear resistance, more affordable. Gold-plated contacts are used in many harsh-environment applications to maintain low contact resistance over time since gold is resistant to oxidation.
The M39029 specification now allows for selective gold plating, which offers all of the benefits of gold plating with significant cost savings.
6. Availability
The availability of copper alloy materials affects manufacturing in two significant ways. The scarcer a metal, the more difficult it is to source and purchase — even at expectedly higher costs. Some types of copper, specifically C97 (a low-alloy copper) and beryllium copper, can be difficult to source, which not only increases their cost, but also the lead-times for contact delivery.
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