The SMA connector(SubMiniature version A) is a 50 ohm coaxial connector. It is visually similar to an F type connector that is commonly used for audio/video communication, but has different dimensions, mechanical properties and is used for different applications such as RF communications up to 18 GHz. Due to its construction, SMA connectors provide a strong and durable connection that minimizes reflections, limiting attenuation, and makes it a great choice when working with microwave frequencies.

SMA Male Connector

The SMA male connector is identified by inside 1/4″-36 threads and a 5/16″ hex nut. A standard polarity connector will have a male pin.


SMA Male Dimensions

  • Outer Diameter: 6.35mm
  • Inner Diameter: 4.59mm
  • Pin Diameter: .97mm
  • Pin Tip Diameter: .38mm

SMA Female Connector

The SMA female connector is identified by outside 1/4″-36 threads. A standard polarity connector will have a female sleeve.

SMA Female Dimensions

  • Outer Diameter: 5.49mm
  • Inner Diameter: 4.60mm
  • Pin Insert Diameter: 1.30mm

Reverse Polarity (RP) SMA Male Connector

The RP SMA male connector is identified by inside 1/4″-36 threads and a 5/16″ hex nut. It will not have a male pin, but will have a female sleeve.

RP SMA Male Dimensions

  • Outer Diameter: 6.35mm
  • Inner Diameter: 4.59mm
  • Pin Insert Diameter: 1.30mm

Reverse Polarity (RP) SMA Female Connector

The SMA female connector is identified by outside 1/4″-36 threads. A standard polarity connector will not have a female sleeve, but will have a male pin.

RP SMA Female Dimensions

  • Outer Diameter: 5.49mm
  • Inner Diameter: 4.60mm
  • Pin Diameter: .97mm
  • Pin Tip Diameter: .38mm

Identifying a RP SMA Connector

If you need help identifying the polarity of a SMA connector, please see this video.

Applications for SMA

SMA connectors are used to terminate flexible or rigid cable. They are used in a variety of military applications including testing, radar, and landing systems. They are also common for wireless or cellular applications such as base stations, satellite communications and antenna connectors.

Finding the Right SMA Connector or Adapter

ShowMeCables carries a wide selection of SMA connectors and adapters. No matter if you are working with thin cable like RG-178 or rigid cable like LMR-600 we have the fittings you need. Shop online to see our entire selection.