Camlock couplings (also known as cam and groove couplings) are widely used across Europe for quick and secure fluid transfer in industrial, chemical, and agricultural applications. Unlike the NPT standard in the U.S. and BSP in the UK, Europe primarily relies on Metric Threads following DIN (Deutsches Institut für Normung) and ISO (International Organization for Standardization) specifications. This article explores the metric thread standards for camlock couplings in Europe, their advantages, and best practices for proper usage.
Metric Thread Standards in European Camlock Systems
In Europe, camlock couplings typically use metric threads defined by:
1. ISO 6149 – Specifies metric threads for fluid power applications.
2. DIN 2353 – Standard for metric fittings in hydraulic systems.
3. ISO 1179 – Covers metric connections for general industrial use.
Key Metric Thread Types for Camlock Couplings:
| Thread Type | Description | Common Use Cases |
| M Thread (Parallel Metric) | Straight threads with a constant diameter, often sealed with an O-ring or washer. | Hydraulic systems, low-pressure fluid transfer. |
| MK Thread (Metric Tapered) | Tapered threads (1:10 taper) that seal via thread deformation (similar to NPT/BSPT). | High-pressure applications, fuel and gas systems. |
| Metric Fine Thread (e.g., M12x1.5) | Finer pitch for better sealing in precision applications. | Automotive, aerospace, and instrumentation. |
Where Metric Threads Are Used in Camlock Systems:
– Hose adapters (connecting to metric-threaded pipes/hoses).
– Coupler and nipple ends (ensuring compatibility with European equipment).
– Interchangeable adapters (for transitioning between metric, BSP, and NPT).
Why Metric Threads Dominate European Camlock Applications
1. Standardization Across Industries – DIN and ISO metric threads are widely adopted in European manufacturing, ensuring compatibility.
2. Precision & Interchangeability – Metric threads follow strict ISO standards, reducing fitting mismatches.
3. Sealing Efficiency – Parallel metric threads (M) use O-rings for leak-proof connections, while tapered (MK) threads provide mechanical sealing.
4. Global Trade Compatibility – Many non-European countries (e.g., China, Japan) also use metric threads, facilitating international equipment integration.
Metric vs. Other Thread Standards in Camlock Couplings
| Feature | Metric (DIN/ISO – Europe) | BSP (UK) | NPT (USA) |
| Thread Angle | 60° (parallel or tapered) | 55° | 60° |
| Sealing Method | O-ring (parallel) / Thread taper (MK) | Washer (BSPP) / Thread (BSPT) | Taper + sealant |
| Common Sizes | M12, M16, M20, MK14x1.5 | G1/2, G3/4, R1/2 | 1/2″ NPT, 3/4″ NPT |
| Industry Preference | Widely used in EU hydraulic & industrial systems | Common in UK & Commonwealth | Standard in North America |
Key Considerations:
– Metric threads are not interchangeable with BSP or NPT—forcing a connection can damage threads.
– O-ring seals (M threads) provide better leak resistance than tape-based sealing (NPT/BSPT).
– Tapered metric threads (MK) are less common but used in high-pressure systems.
