What Is ST Connector? Complete Guide

ST Connector

What is ST connector? A quick-release bayonet style connector, straight tip (ST) connectors are most frequently used in fiber optic networking applications.

Keep reading and learn more about ST connectors.

Features And Applications Of ST Connector

Features And Benefits

  • Complies with IEC 61754-2 and TIA 604-2-B, FOCIS-2
  • Low insertion loss and back reflection capability
  • Bayonet style (stick and twist) housing for easy connection
  • Nickel-plated metal body
  • Zirconia ceramic ferrule is available in several performance grades
  • RoHS materials, REACH SvHC compliant
  • Individual parts packed in bulk package


  • Local area networks
  • Data processing networks
  • Distribution application
  • Premises distribution

What Does ST Connector Mean?

A straight-tip connector (ST connector), which uses a bayonet-style plug and socket, is used in fiber-optic cables. It is now widely accepted as the norm for business wiring. Since the ST connector configuration permits unidirectional communication, bidirectional communication is accomplished using two ST connectors and two fiber cables.

ST Connector

Techopedia Explains ST Connector

The straight-tip connector has a 2.5-mm keyed ferrule and a quick-release bayonet-style connector that is cylindrical with a twist-lock coupling. It was created by AT&T and dominated long-line systems and short-distance applications in the 1980s and 1990s. The ST connector’s straight ferrule, which is a rigid plastic tube used to hold the fiber in the correct alignment for interconnection or termination, is its most noticeable feature.

ST connectors are spring-loaded, making it simple to insert and remove them, but you must make sure they are properly seated to prevent light loss. Insertion loss usually amounts to 0.25 dB. Both single-mode fibers and multi-mode fibers can be used with the connector, which has a 500 mating cycle rating.

Read More: DIN Connector