19-Inch Rack: Server Racks, Rack Cabinets, and Rackmount Systems

Introduction: What Is a 19-Inch Rack?

A 19-inch rack, also called a server rack or rack cabinet, is a standardized frame for mounting electronic equipment modules. Each device has a front panel measuring 19 inches (482.6 mm) wide, including the mounting ears used to fasten it to the rack with screws or bolts.

Common applications of 19-inch racks include:

• Computer servers and IT hardware

• Telecommunications and networking equipment

• Audiovisual production gear

• Professional audio equipment

• Scientific and industrial instruments

Overview and History of Rackmount Systems

Equipment designed for racks is described as rack-mountable or rackmount enclosures. Module height is standardized in multiples of 1.75 inches (44.45 mm), known as a rack unit (U). The typical rack cabinet is 42U tall, but modern data centers often use taller racks.

• The term relay rack originated in telephony.

• By 1922, AT&T introduced the 19-inch rack to optimize telephone repeaters.

• In 1934, the format was formalized with mounting holes and standardized dimensions.

• The Electronic Industries Alliance (EIA) later refined the unit definition, making 1U exactly 44.45 mm (1.75 in).

Despite evolving technology, the 19-inch server rack remains the global standard for computing, telecom, audio, and scientific industries.

Benefits of 19-Inch Server Racks

• Space efficiency – Vertical mounting saves valuable floor space.

• Scalability – Easy to expand and reconfigure.

• Cooling optimization – Supports airflow management in data centers.

• Cable management – Keeps installations organized and service-friendly.

• Universal compatibility – Works with equipment from different manufacturers.

Types of 19-Inch Racks

Four-Post Cabinet Racks

• Most common in data centers

• Front and rear mounting for better support

• Can be open-frame or enclosed

Two-Post Relay Racks

• Lightweight design

• Used in telecom installations for switches, routers, and patch panels

Specialty Racks

• Soundproof server racks for office environments

• Seismic-rated racks for earthquake safety

• Air-conditioned racks for high-density heat loads

• NEMA-rated racks for industrial/outdoor use

Portable Road Case Racks

• ATA-approved flight cases

• Used by musicians, AV companies, and touring productions

Rack Units and Dimensions

• 1U = 1.75 inches (44.45 mm)

• Standard height: 42U (about 2 meters)

• Width: 19 inches (482.6 mm)

• Depth: typically 600 mm, 800 mm, or 1,000 mm

This modular design makes the 19-inch rack cabinet highly flexible for IT, telecom, and AV setups.

Equipment Commonly Mounted

• Servers and networking gear – routers, switches, storage systems

• Telecom equipment – PBX systems, signal processors

• Professional audio gear – amplifiers, mixers, effects units

• Video production equipment – encoders, AV routers

• Industrial automation hardware – power distribution, controllers

Cooling and Power Management

Efficient cooling is critical in rack cabinets. Standard practices include:

• Front-to-rear airflow for servers

• Cold aisle / hot aisle containment in data centers

• Zero-U PDUs (Power Distribution Units) and vertical cable managers

• Sealed and filtered enclosures to reduce dust

Rack Standards Beyond 19-Inch

• 10-inch racks – compact format for hobbyists and small setups

• 23-inch racks – legacy telecom racks

• ETSI 21-inch racks – common in European telecom installations

• Open Rack (OCP standard) – for hyperscale computing

• Eurorack / Eurocard – widely used in music production and PCB enclosures

Conclusion

The 19-inch rack has been the universal standard for over a century, enabling dense, scalable, and efficient infrastructure across IT, telecom, AV, and industrial applications.

Whether building a data center in Stockholm, upgrading telecom infrastructure in Gothenburg, or managing professional AV gear in Malmö, the 19-inch server rack cabinet provides unmatched flexibility and reliability.

With a supplier like Etm4u businesses can easily access world-class rack solutions tailored to their needs.