Rugged Cadmium-plated Connectors in Marine Environments

Whether in naval equipment or other marine applications, Sunkye connectors offer the cadmium plating option.

Why is cadmium plating often designed for marine applications such as naval equipment, not for aerospace applications?

On average, seawater in the world's oceans has a salinity of about 3.5%, it is rich in natural electrolytes and highly corrosive. Seawater can destroy the oxide film on the surface of metal and form a complex with metal ions, which produce hydrogen ions during hydrolysis, so that the acidity of seawater increases, and the local corrosion of the metal is strengthened. Therefore, a metal surface finish is necessary, a better choice would be cadmium plating. As a protective surface finish, cadmium plating offers great connectivity and withstands corrosion and salt spray, matching most marine applications.

Generally, cadmium is not applied in aerospace environments. Most aerospace applications do not involve salt spray and corrosion issues, and it is a toxic substance that cannot be applied in manned spaceflight equipment. Cadmium will sublimate in a high vacuum environment (especially when the temperature is higher than 75 degrees Celsius), and the sublimated substance will conduct electricity and cause a short circuit.

Faced with continued demand for more robust designs, Sunkye connectors provide corrosion and vibration resistance, higher mating cycles, and extended operating temperature ranges for marine applications in the harshest environments without performance degradation.

Sunkye D38999 series III connector specifies cadmium-plated aluminum alloy shells, it offers high corrosion resistance (500-hour salt spray exposure), high shock and vibration (vibration testing to 2940m/s2 3ms), and provides superior EMI shielding capability of 50dB min, up to 500 mating cycles for the plug and receptacle, and the operating temperature range is from –65˚C to 175˚C.

Reliability, sealing, and durability are critical to performance in harsh environmental conditions. Sunkye D38999 III cadmium-plated connectors can withstand humidity, corrosion, salt spray, and particulates, meeting the operating conditions of oil extraction and naval equipment.

Sunkye D38999 III cadmium-plated connectors' specifications:


Test Results

Working Temperature


Insulation Resistance

≥5000 MΩ


500 mating cycles


10 Hz~2000Hz,147m/s2


2940m/s2  3ms

Salt Spray


Humidity Resistance

24h each cycle, 10 cycles

Sunkye D38999 III cadmium-plated connectors' specific requirements include:
☑ Meet MIL-DTL-38999 III specification
☑ High Reliability, high durability
☑ 500-hour salt spray exposure
☑ High resistance to corrosion
☑ Superior EMI shielding capability of 50dB min
☑ Widely used in naval equipment and oil drilling equipment

Sunkye Connection Technologies provides a wide product portfolio with a complete interconnect solutions offering. Sunkye connectors and cables assemblies are complementary with Sunkye backshells and conduits.