Brass fittings play a crucial role in countless fluid, air, and gas handling systems across industries. Known for their excellent corrosion resistance, durability, and machinability, brass fittings are commonly used in plumbing, pneumatics, hydraulics, refrigeration, fuel systems, and industrial automation. Their widespread application is not just due to material properties but also because of the diverse types of fittings that can be manufactured to suit various system requirements.
In this guide, we explore the main categories of brass fittings used globally and explain how each type functions, where it’s typically applied, and what advantages it offers in the broader industrial landscape.
Compression Fittings
Compression fittings are widely used in instrumentation and plumbing systems where leak-proof joints are essential but welding or soldering is either not possible or not preferred. These fittings consist of a body, a nut, and a ferrule (also called an olive), which compresses against the pipe or tube as the nut is tightened. This creates a tight seal through mechanical pressure, without the need for heat or thread sealants.
They are compatible with both plastic and metal tubing, making them versatile for a range of applications. The ability to disassemble and reassemble them without damaging the components adds to their popularity in maintenance-intensive industries such as HVAC and pneumatic control systems.
Flare Fittings
Flare fittings are designed for high-pressure systems where vibration or pulsation may compromise other types of joints. These fittings require the end of a tube to be flared (typically to a 37° or 45° angle), which is then compressed against a matching cone in the fitting. This metal-to-metal seal is reliable, reusable, and especially suitable for environments where leaks are unacceptable, such as refrigeration systems, gas lines, and hydraulic brakes.
Unlike compression fittings, flare fittings do not use ferrules, which simplifies internal geometry and reduces dead space—an important factor in systems carrying volatile gases or fluids. Their mechanical strength and leak integrity make them a preferred choice in automotive and aerospace assemblies.
Pipe Fittings (Threaded)
Threaded pipe fittings are some of the most recognizable types used in global plumbing and fluid transfer systems. They are designed to connect threaded pipe ends using standardized thread profiles like NPT (National Pipe Thread), BSP (British Standard Pipe), or ISO metric threads. Available in many shapes such as elbows, tees, reducers, and plugs, these fittings serve as essential building blocks for pipe routing and system layout.
One of their major benefits is compatibility with a wide range of pipe materials including steel, copper, and plastics. Threaded fittings are ideal for both low- and high-pressure systems, although proper sealing techniques—such as PTFE tape or anaerobic sealants—must be used to prevent leakage. They’re commonly found in irrigation networks, air compressors, industrial machinery, and chemical distribution systems.
Push-to-Connect (Push-In) Fittings
Push-to-connect fittings represent a major step forward in simplifying the assembly of pneumatic and fluid lines. These fittings allow for tool-less connection: the tube is simply pushed into the fitting, where an internal grab ring holds it in place, and a rubber O-ring forms the seal. This design allows for incredibly fast installation and removal, significantly reducing labor time.
Typically used with soft tubing like polyurethane, nylon, or polyethylene, push-in fittings are extremely popular in automation, robotics, and packaging industries. In transport systems—especially for air brake lines—DOT-approved versions are used in compliance with safety standards. Metric and inch-size variants are available, ensuring global compatibility.
Barbed Hose Fittings
Barbed fittings are intended for flexible hose connections and rely on a series of ridges (barbs) to grip the interior of a hose. When combined with hose clamps, they offer a secure and leak-resistant connection for low to medium-pressure systems. These fittings are simple, cost-effective, and easy to install, making them a common choice in industries like agriculture, beverage dispensing, and general-purpose fluid handling.
Because they don’t require threading, barbed fittings are ideal for field repairs or temporary setups. They are, however, best used where the hose and fitting can be matched precisely in diameter, and where regular disconnection is not required.
Adapters and Couplings
Adapters and couplings serve the critical function of bridging different sizes, thread types, or connection styles. In industrial settings, systems often involve legacy parts, imported components, or region-specific standards. Adapters such as BSP-to-NPT converters or male-to-female reducers ensure compatibility without the need for re-engineering a system.
Couplings, on the other hand, are used to extend pipelines or connect similar fittings. They are especially useful in maintenance, allowing damaged segments to be replaced without disturbing the entire line. High-precision industries like oil & gas and food processing often require brass adapters and couplings that meet both performance and hygiene standards.
Custom and Specialty Brass Fittings
While standard fittings meet most general needs, some industries demand highly specialized brass fittings designed for non-standard thread types, unique pressure requirements, or special environments. Custom brass fittings can be machined to customer drawings, allowing precise tolerances, knurled features, or even multi-port configurations.
Such fittings are commonly used in OEM projects, prototyping, automotive sensor housings, or pressure-sensitive hydraulic applications. With global industries pushing for localization, component traceability, and performance guarantees, the demand for small-batch, high-precision fittings is steadily growing.
Conclusion
Brass fittings remain integral to countless systems where fluid or air handling is critical. From basic plumbing tasks to high-end pneumatic control and automotive braking, the variety of brass fitting types reflects the broad demands of global industries. Selecting the correct type is not only a matter of mechanical compatibility but also involves understanding system pressure, material standards, environmental exposure, and maintenance access.
As industries advance toward automation, tighter tolerances, and global interoperability, brass fittings will continue to evolve—both in design and in the way they are manufactured and certified.