What are the most common hydraulic threads？

Hydraulic adapters are essential key components in hydraulic systems. Their function is to connect hydraulic components together, forming a complete hydraulic system, and to facilitate the transmission of hydraulic energy for corresponding mechanical operations. As one of the most commonly used connection methods in hydraulic systems, threaded joints are widely applied in various hydraulic equipment and industrial fields. Their importance lies in the fact that threaded joints possess characteristics such as high strength, stability, and durability, enabling them to withstand high pressure, large flow rates, and complex working conditions involving pressure fluctuations. In the production process, we need to continuously explore innovations and update the technology and design of hydraulic adapters based on customer demands and market changes to meet the usage needs in different fields. Below are the six common threaded forms of hydraulic adapters.

1.UN/UNF (Unified National/Fine Thread)

UN/UNF is a standard for straight threads established by the American National Standards Institute, officially known as Unified National/Unified Fine Thread. It is commonly used in the manufacturing process of hydraulic adapters. The design goal of UN/UNF is to provide a connection method that offers high strength, high load capacity, and excellent sealing in high-pressure, high-flow environments. Compared to other thread types, UN/UNF has stricter and more precise technical parameters, making it widely applicable not only in hydraulic equipment but also in various other industrial fields. Adhering strictly to UN/UNF standards during the processing and quality inspection of hydraulic adapters is essential for ensuring their quality, performance, and safety. At our factory, we consistently uphold the principles of quality first and customer foremost, striving for innovation and continually improving our technology and processes to enhance product quality and performance, thereby providing our customers with high-quality hydraulic adapters and hose fittings.

2.NPT/NPTF (National Pipe Thread/Tapered Fuel)

NPT/NPTF is the American standard for pipe threads, officially known as National Pipe Thread/National Pipe Tapered Fuel. This thread standard is widely used for pipe and hose connections, designed to achieve a self-sealing connection. NPT/NPTF threads are characterized by their tapered shape, which uses a special angle design to create a self-sealing effect when tightened, eliminating the need for additional sealing washers or materials. As a result, NPT/NPTF threads are commonly used in various hose and pipe systems, suitable for low to medium pressure environments.

3.BSPP (British Standard Pipe Parallel)

BSPP, also known as British Standard Pipe Parallel, is a British standard for straight pipe threads. This standard falls between American and European thread types and is primarily designed for applications with lower flow requirements. Compared to other thread standards, BSPP threads are widely used in low to medium pressure hydraulic systems and pipe connections, as well as in various other industrial and civil applications. BSPP threads are parallel, which means they do not form a seal on their own, necessitating the use of additional sealing washers or materials to achieve a sealing effect.

4.BSPT (British Standard Pipe Taper)

BSPT, also known as British Standard Pipe Taper, is a British standard for tapered pipe threads. This thread standard is widely used in hydraulic systems, primarily designed to achieve stable connections in high-pressure and high-flow environments. Compared to other thread standards, BSPT features a tapered design where the angle between the threads gradually decreases, resulting in a self-sealing effect that does not require additional sealing washers or materials for effective sealing. Consequently, BSPT threads are commonly used in high-pressure, high-flow hydraulic and piping systems.

5.Metric Straight Threads

Metric straight threads, also known as G threads, are a common thread standard used in fluid systems, gas systems, mechanical systems, and other industries that operate under the metric system. The design goal of metric straight threads is to provide stable connections and sealing effects in low-load, low-flow environments. Due to their parallel design structure, metric straight threads do not possess sealing capabilities on their own, necessitating the use of sealing washers or other compensating sealing materials during connection to achieve a stable sealing effect. Compared to other thread connection methods, metric straight threads are typically used in applications such as level gauges, pressure gauges, flow meters, and low-load, low-flow piping.

6.Metric Tapered Threads

Metric tapered threads, also known as R threads or conical threads, are widely used in hydraulic systems, pneumatic systems, mechanical systems, and other fields. Their design feature is that the angle between each thread gradually decreases, achieving a self-sealing effect that does not require additional sealing washers or other materials to achieve good sealing performance. As a result, metric tapered threads are usually suitable for high-pressure, high-flow applications, providing stable and reliable connections. Compared to metric straight threads, metric tapered threads are better suited for high-flow scenarios and can withstand higher pressures and loads.