Threaded Connectors: 5 Key Types You Should Know

Threaded connectors are essential components in various industries, providing secure and reliable connections in piping systems, machinery, and equipment. Understanding the different types of threaded connectors is crucial for selecting the right one for your application. Here, we demystify the world of threaded connectors by highlighting five key types you should be familiar with.


  1. NPT (National Pipe Tapered)

NPT is the most common type of threaded connector in North America. It has a tapered thread that seals by fitting the male and female threads tightly together, creating a mechanical lock. NPT connectors are used in a wide range of applications, from water and gas pipes to hydraulic systems.


  1. BSPT (British Standard Pipe Tapered)

Similar to NPT, BSPT threads are designed to make a tight seal through thread interference. They are commonly used in the UK and other countries that follow British standards. BSPT connectors are suitable for transporting water, steam, and air.


  1. BSPP (British Standard Pipe Parallel)

BSPP connectors, also known as G or Rp threads, have parallel threads and are used with a bonded seal ring that fits between the male and female threads. This type of connector is ideal for applications where a fluid-tight seal is required on the port face.


  1. Metric Tapered

Metric tapered threads are similar to NPT but follow the metric system. They are often used in Europe and Asia and are suitable for a variety of applications, including pneumatic and hydraulic systems.


  1. UN/UNF (Unified National)

UN threads are a series of standardized thread types that include a variety of forms such as UNR (rounded root) and UNJ (aerospace). UNF (Unified National Fine) is a subset with a finer thread pitch than the standard UN. These connectors are used in applications requiring precision and strength.



Threaded connectors are a vital part of many systems, and choosing the right type is essential for ensuring a secure and leak-free connection. Whether you’re working with water pipes, hydraulic systems, or machinery, understanding these five key types of threaded connectors will help you make an informed decision for your specific needs.