Technical Support for Antennas & Related Gear

SMA Connectors Specifications, Applications, Composition, and Characteristics

George Hardesty
2 minute read

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SMA Characteristics and Key Points

  • SMA is often confused with RP-SMA (Reverse-Polarity SMA). SMA is more typically used in cellular wireless, GPS, and HAM radio applications, while RP-SMA is more commonly used with Wi-Fi, Bluetooth, ZigBee, and LoRaWAN (in the United States).
  • SMA female connector is also called "jack" and SMA-male is also called "plug."
  • SMA is a round screw-type connector, with medium-sized, threaded coupling connectors that are rated for frequencies from the lowest (DC) up to 18GHz.
  • SMA gender is counter-intuitive: The bender is based on the orientation of the pin and socket (on the interior of the threaded section of the body): Male has a pin and female has a socket.

SMA Materials Composition of Male and Female Connectors

SMA-Connector Materials Composition

  • Connector Body:
    • SMA connectors that are on antenna cables have a gold-plated brass body (in almost all cases), because this is the best alloy for the connector-body, if intended for indoor use.
    • SMA adapters that are expected to be exposed to water or weather have a nickel-plated brass body for protection from rust and corrosion.
    • SMA connectors for cables and antennas, if they will have weather exposure, can be made with a nickel-plated brass body for corrosion protection.
  • Center Contact: Beryllium Copper, Gold Plated
  • Crimp Ferrule: Nickel Plated Copper
  • Insulators: PTFE

SMA male and female diameter

  • SMA female outside diameter is 5/16" (7.9375mm): Accommodates a hex nut (bulkhead nut) with 5/16" nominal outer diameter
  • SMA male inside diameter is 5/16" (7.9375mm) (the inside diameter where the threads are).


  1. We offer an SMA wrench to assist in installing antennas, SMA cables and adapters with SMA or RP-SMA connector(s).

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