What is a compressed air coupling?

A compressed air coupling – also known as a quick coupling – is a key connection element in any compressed air system. It enables fast and secure connection of air lines to tools or machines, ensuring continuous airflow and allowing for quick tool changes without interrupting the system.

Whether in workshops or industrial settings, the right quick coupling increases efficiency, minimizes leaks, and ensures smooth operation.

Wide selection of quick couplings by bore size

Compressed air quick couplings are available in various bore sizes, tailored to different applications. You can use our online shop’s filter function to search for specific bore sizes.

Here are some of the most common bore sizes in our range of quick couplings:

• Bore 1.5 mm (Series 02)
• Bore 2.7 mm (Series 20)
• Bore 5 mm (Series 21)
• Bore 5.5 mm (Series 14, 18, 19, 22, 23, 24, 1400)
• Bore 7.2 mm (Series 26 – standard workshop coupling)
• Bore 7.8 mm (Series 25, 1600)
• Bore 10 mm (Series 27, 34, 41, 1700)
• Bore 15 mm (Series 38)
• Bore 19 mm (Series 39)

Choosing the right quick coupling depends on your required air volume and application – from portable systems to large-scale industrial setups.

Bore 7.2 mm – the workshop standard

The most widely used compressed air coupling is the 7.2 mm bore model. It delivers excellent airflow while remaining easy to use and is found in nearly every workshop. The standard coupling used here comes from Series 26, and most workshop compressors are designed for this type.

Available in many materials and finishes, it can be adapted to suit various conditions. The classic version is a bare brass quick coupling – proven and affordable.
Check out the full Series 26 in our shop. We've also explained how our "talking part numbers" work for easier orientation.

Flexibility within the same bore size

One of the key advantages of modern quick couplings is the ability to mix and match sockets and plugs within the same bore size. This greatly simplifies daily use – whether for maintenance work, tool changes, or mobile setups.

Example:
Need to swap a blow gun for a tire inflator? Just disconnect the old tool and plug in the new one – no venting or system shutdown required.

Safety Tip: Always hold both parts securely when connecting or disconnecting, as pressure is usually present in the line.
Self-venting quick couplings – with or without push-button release – offer a safer way to disconnect, preventing the "whiplash effect."

Quick couplings with or without shut-off

Besides open-flow couplings, there are two shut-off variants that help prevent air escaping when disconnected:

• Single shut-off compressed air coupling: Stops airflow on the socket side only – simple and effective.
• Double shut-off quick coupling: Stops the flow on both socket and plug sides – ideal when air loss must be avoided during tool changes.

Note: Double shut-off plugs only work with compatible double shut-off sockets, which contain the necessary pin to open the plug valve.

Durable materials for every environment

Compressed air quick couplings are available in a range of materials to suit different operating conditions. Our selection includes:

• Brass (for -20 °C to +100 °C)
• Stainless steel (up to +200 °C, ideal for food or chemical industries)
• Zinc-plated steel (corrosion-resistant and robust)
• Plastic (POM or PVDF) – often used in medical environments
• Aluminum – especially for our ergonomic, self-venting couplings with push-button release

“Hard-material” couplings can withstand operating pressures up to 35 bar, while plastic or aluminum couplings are rated for lower pressures (typically 10–15 bar depending on the model).

Compatibility with other brands

Our quick couplings are compatible with many major brands, making it easy to upgrade or extend existing systems.
You don’t need to replace your entire setup when switching suppliers – a major plus when sourcing replacements or expanding equipment.

Seal materials

Quick couplings are made with various seal materials, chosen according to the medium being conveyed. While water at 20 °C is easy to manage, hot oil or kerosene require more specialized seals.

In compressed air applications, the seal material is generally not critical – almost all types handle air pressure well. NBR is the standard choice here.

To seal threaded connections on shut-off couplings or male plugs, we recommend using RectuLoc sealing compound or adding a capative washer at the thread entry.

Applications for compressed air quick couplings

Quick couplings for compressed air are used wherever efficient air flow is essential:

• Industrial systems: reliable, uninterrupted air supply
• Workshops: for blow guns, impact wrenches, tire inflators
• Production & assembly: tool changes without downtime

Conclusion: Find the right compressed air coupling for your needs

Whether you're outfitting a workshop, upgrading an industrial system, or setting up mobile tools – we offer reliable, compatible, and durable compressed air couplings for every application.
Choose from various bore sizes, materials, and shut-off features.

Need help choosing the right coupling? Our experts are happy to advise you – by phone, email, or live chat.