Quick Answer: HYSF connectors use American Unified Thread (UNF) standards. The closest replacement for M16 is 5/8″-18 UNF-2A from our MCBH Series. If you can modify your mounting hole, we recommend the Round Small Series (3/8″-24 UNF) or Ultra Small Series (5/16″-24 UNF) for lighter weight and better cost-effectiveness.
Detailed Explanation
Many international customers design their underwater sensors with M16 metric threads. However, HYSF manufactures connectors according to American Unified Thread standards. Here’s how to find the right replacement:
Thread Compatibility Chart
| HYSF Series | Thread Size | Closest Metric Equivalent | Best For |
|---|---|---|---|
| MCBH Series | 5/8″-18 UNF-2A | M16 (closest match) | Direct M16 replacement |
| Round Small Series | 3/8″-24 UNF-2A | M10 | Compact sensors, lighter weight |
| Ultra Small Series | 5/16″-24 UNF-2A | M8 | Miniature applications, cost-effective |
Key Considerations for M16 Replacement
- Mounting Hole Modification: If your sensor housing design allows, switching to Round Small or Ultra Small series offers significant advantages in weight reduction and cost savings.
- Sealing Performance: All HYSF connectors feature single or double O-ring sealing. For most underwater applications, single O-ring provides sufficient protection.
- Material Options: Choose from Stainless Steel 316L (standard), Aluminum Alloy, or Titanium Alloy based on your corrosion resistance requirements.
- Pin Configuration: All three series offer 4-pin models suitable for RS485 communication and other signal transmission applications.
Installation Configuration
For water quality monitoring sensors and similar applications:
- Male Bulkhead: Installs on the sensor probe side (threaded into probe cap)
- Female Connector: Assembles on the cable side
- Cable Assembly: Can be supplied with pre-terminated cable (e.g., 10 meters, 4×0.5mm²) with free ends for your RS485 system connection
Expert Recommendation
If you’re designing a new sensor system, we recommend the Round Small Series for the best balance of performance, size, and cost. For existing M16 designs that cannot be modified, the MCBH Series with 5/8″-18 UNF thread provides the closest compatibility.
Need Help? Contact our technical team at info@hysfsubsea.com with your specific requirements. We’ll provide datasheets, pricing, and custom cable assembly solutions within 24-48 hours.









