The SC connector is one of the most recognizable and widely used interfaces in fiber-optic communication. Known for its push-pull locking mechanism, robust mechanical strength, and high degree of standardization, the SC connector remains essential in FTTH, ODF systems, data centers, and telecom networks worldwide.

Although SC connectors may look simple from the outside, each model—0.9 mm, 2.0/3.0 mm, duplex, and uniboot—contains a precisely engineered internal structure designed for optical stability and long-term reliability. This article breaks down the structure of SC connectors using engineering drawings and real component photos (Figures SC-1 to SC-6), explaining the purpose of each component and the differences among various SC designs

TABLE OF CONTENTS

SC Connector Overview

SC Series Connector Exploded Views

Figure SC-01

The engineering overview in Figure SC-1 illustrates the complete structure of an SC connector. Regardless of size or variant, every SC connector is built from a set of core components:

  • Ferrule Assembly – the optical core containing the zirconia ferrule
  • Inner Housing – holds the ferrule in precise alignment
  • Spring – maintains stable physical contact
  • Outer Housing – the blue or green shell that locks into adapters
  • Main Body – central structural part connecting the front and rear sections
  • Crimp Ring + Crimp Sleeve – secures the Kevlar yarn of 2.0/3.0 mm cables
  • Boot – protects the cable and prevents over-bending

Different SC versions simply adapt these components to the cable size and application needs.

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SC 0.9 mm Structure

SC Connector 0.9 mm Structure

Figure SC-02

The SC 0.9 mm connector is a simplified and lightweight version designed for pigtails and internal equipment wiring. Because 0.9 mm pigtail fiber has very little Kevlar, this structure does not include a crimp ring or crimp sleeve.

Structure Components

  • Outer Housing
  • Inner Housing
  • Ferrule Assembly
  • Spring
  • Main Body
  • 0.9 mm Boot

This design is compact, easy to assemble, and ideal for applications where high tensile strength is not required.

SC 1.2 / 2.0 / 3.0 mm Structure

SC Connector 1.2 / 2.0 / 3.0 mm Structure

Figure SC-03

This is the standard and most widely used SC connector structure. It is designed for patch cords where the fiber cable contains Kevlar yarn that must be securely fixed inside the connector.

Compared with the 0.9 mm version, this structure adds a crimp system consisting of:

  • Crimp Ring – clamps the Kevlar yarn
  • Crimp Sleeve – reinforces the rear section for long-term stability

Structure Components

  • Outer Housing
  • Inner Housing
  • Ferrule Assembly
  • Spring
  • Main Body
  • Crimp Ring
  • Crimp Sleeve
  • Boot (1.2/2.0/3.0 mm depending on cable design)

This version is the default structure for SC patch cords used in FTTH, ODF frames, and telecom networks.

SC Duplex Structure

SC Connector Duplex Structure

Figure SC-04

An SC duplex connector is essentially two simplex SC connectors held together with a duplex clip. This clip is composed of:

  • Upper Clip
  • Lower Clip

Duplex SC connectors are commonly used in applications requiring bidirectional transmission, such as switches, transceivers, and ODF panels.

Structure Components

Each side contains:

  • Outer Housing
  • Inner Housing
  • Ferrule Assembly
  • Spring
  • Main Body
  • Crimp System
  • Boot

The duplex clip allows technicians to easily separate or combine the connectors during installation.

SC Uniboot Structure

SC Connector Uniboot Structure

Figure SC-05

The SC uniboot connector is designed for high-density data center applications. It routes two fibers into a single boot, significantly reducing cable volume and improving airflow inside racks.

A key feature of this design is the Polarity Reversal Frame, which allows technicians to switch polarity (A-B ↔ B-A) without re-terminating the connector. This is critical in modern data-center cabling systems.

Structure Components

  • Outer Housing
  • Inner Housing
  • Ferrule Assembly
  • Spring
  • Main Body
  • Crimp Ring
  • Crimp Sleeve
  • Polarity Reversal Frame (for quick polarity switching)

  • Uniboot Tail Boot

Compared with duplex SC, the uniboot design offers cleaner cable management and faster deployment in high-density environments.

SC Component Overview

SC Connector Component Overview

Figure SC-06

Figure SC-6 shows a collection of SC boots, ferrules, dust caps. These parts follow industry color standards:

  • Blue → SC/UPC
  • Green → SC/APC
  • Beige/Cream → multimode
  • Boots vary by cable size (0.9 / 2.0 / 3.0 / uniboot)

Ferrules are typically made of zirconia ceramic, and dust caps protect the ferrule endface during transport and storage.

SC vs LC: What’s the Difference

Feature SC Connector LC Connector
Ferrule Size
2.5 mm
1.25 mm
Connector Size
Larger
Smaller / high-density
Locking Mechanism
Push-pull latch
Push-pull latch (smaller body)
Typical Use
FTTH, ODF, telecom
Data centers, high-density panels
Duplex Format
Two SC + duplex clip
LC duplex / uniboot
Uniboot Availability
Yes (less common)
Very common
Insertion Loss Performance
Standard
Excellent for dense systems
Typical Environments
Access networks, outdoor
Data center, enterprise LAN

In short:

  • SC = robust, standardized, widely used in FTTH & telecom
  • LC = compact, optimized for high-density data-center cabling

Both remain essential in modern optical communication.

Manufacturing Notes: What Affects SC Performance

High-quality SC connectors rely on:

  • Ferrule concentricity and polishing quality
  • Precision of inner housing and main body
  • Spring force consistency
  • Crimping reliability
  • Plastic part stability under temperature changes

YingFeng Communication manufactures SC components and connector kits with strict process control and large-scale production capability, ensuring compatibility with global telecom standards and consistency across high-volume orders.

FAQ — Common Questions About LC Connector

What is the main difference between SC 0.9 mm and SC 2.0/3.0 mm connectors?

The 0.9 mm version has no crimping components and is used for pigtails.
The 2.0/3.0 mm versions include a crimp ring and crimp sleeve to secure the Kevlar yarn, making them suitable for patch cords.

It is a sliding frame that allows technicians to switch polarity (A-B ↔ B-A) without reassembling or re-terminating the connector.

Standard SC connectors are larger than LC connectors, but SC uniboot reduces cable bulk and is suitable for moderate-density applications.

Blue indicates UPC polish, green indicates APC polish. The color helps technicians quickly identify connector type and ensure correct matching.

SC duplex connectors are used in bidirectional transmission, such as network switches, media converters, and patch panel interconnections.

Conclusion

The SC connector remains one of the most important interfaces in fiber-optic communication. By understanding how each SC version is constructed—0.9 mm, 2.0/3.0 mm, duplex, and uniboot—engineers and procurement teams can make better decisions when selecting the right connector structure for their applications.

Clear structural knowledge also reduces installation errors and ensures long-term network stability.