Mil-Spec Connector Materials & Finishes

The First Line of Defense

Finishes for Military Connectors

Connectors are made from a wide variety of materials. Each material has unique benefits and should be selected according to application-specific concerns. Milnec cylindrical connector shells and components are engineered exclusively from high-grade aluminum alloys to withstand the harshest environments and the roughest handling. Metal connectors provide the benefit of impact resistance and reliability. For specialty applications with specific material requirements, connectors can be manufactured from stainless steel, titanium, brass, and advanced lightweight composites.

The finish, or plating, is the protective layer that coats the connector’s foundation material. This coating is the connector’s supplemental defense against corrosion and can be made conductive to provide shell-to-shell electrical continuity for EMI/RFI shielding applications. In addition to standard finishes, Milnec provides a wide selection of specialty finishes to meet the requirements of nuclear, marine, medical, and space applications. RoHS compliant finishes are also available to provide more environmentally friendly plating options for new designs. For the full list of materials and finishes available, please see the materials and finishes page of a specific connector series.

Standard Materials



Milnec cylindrical connectors come standard in aerospace-grade aluminum, which provides high-reliability and strength. Aluminum offers a lightweight, durable, yet economical material option, perfect for anything from general duty to military applications. Aluminum’s natural corrosion resistance is further enhanced by a finish (i.e., plating), which also dictates the appearance of the component and ensures it aesthetically matches the equipment or application’s material requirements.

PS Series Wall Mount Receptacle

Carbon Steel

Carbon steel is used for Milnec’s hermetic receptacle shells. As one of the hardest metals available, carbon steel is extremely tough and maintains its integrity under the harshest conditions and temperature extremes. This makes it ideal for applications requiring hermetic sealing in the most demanding applications such as high-pressure differentials, cryogenics, and high-temperature environments. Stainless steel hermetic connector shells are available by special order.

T9 Hermetic Jam Nut Thru-Bulkhead Receptacle


Electroless Nickel

Electroless Nickel is the default plating for Milnec’s hermetic receptacles. It is also available as a standard finish for most crimp style connectors. The finish enhances wear resistance, corrosion resistance, and durability. It is RoHS compliant and electrically conductive, making the finish an ideal option for EMI sensitive applications. The bright metal look matches many laboratory and aerospace design aesthetics.

Olive Drab Cadmium

Olive drab cadmium plating is a standard finish for all Milnec connectors due to its high corrosion resistance. This finish is conductive, making it suitable for shielding or grounding applications, and is resistant to galling. Its olive drab appearance matches most military equipment. Olive drab cadmium is suitable for all general duty, industrial, military, and marine applications.