Threaded fittings for pipe connections
Threaded fittings connect pipe sections, valves and other threaded components. The selection includes brass, stainless steel and malleable iron, as well as double nipples, pipe nipples, couplings, elbows, tees, crosses, reducing fittings, plugs and union fittings. To choose the right fitting, consider the connection end, thread size, shape and, for pipe nipples, the specified length.
Threaded fittings are threaded connection parts for pipework and valves. Here you can compare material, shape, connection end, size and – for pipe nipples – length. Brass, stainless steel and malleable iron are listed alongside double nipples, pipe nipples, couplings, elbows, tees, crosses, reducing fittings, plugs and union fittings. Product names provide the relevant details, so shapes and dimensions do not have to be confused with one another.
Four steps to the right connection
A clear selection follows a fixed sequence: First choose the material based on the pipe environment, then determine the shape based on the pipe layout. Next match internal or external threads with the connection size. For pipe nipples, add the required length. The details should be shown in the same notation on the mating part and the selected item.
1. Material
Match brass, stainless steel or malleable iron to the intended application.
2. Shape
Choose a straight connection, change of direction, branch, wall connection or termination.
3. Thread
Compare external and internal threads and the size at both connection ends.
4. Length
For pipe nipples, include the specified millimetre value in the planning.
Material as the first choice: brass, stainless steel or malleable iron
Material is the first filter. Match it to the medium and the environment of the planned pipework; depending on the design, product descriptions specify plumbing, heating, air conditioning, solar, water or gas installations.
Brass
Brass fittings appear as double nipples, tees, elbows, crosses, reducing fittings, couplings, wall plates and straight unions. The brass products described specify CW617N brass. The texts list cold and hot water as well as plumbing, heating, air-conditioning and solar technology.
Stainless steel
Stainless steel is represented by double nipples, reducing nipples, couplings, pipe nipples, elbows, wall elbows, crosses, plugs and unions. The product data for the items described specifies stainless steel and V4A. Shapes and connection sizes vary by item.
Malleable iron
Malleable iron appears as couplings, socket nipples, bends, elbows, crosses, tees, angle distributors, wall plates, unions and plugs. The wall plates and angle distributors described specify a galvanized surface. The specific design is stated for each product.
Material and connection size are separate details. A brass double nipple with 1 inch external thread x 1 inch external thread therefore has to be selected using different data than a galvanized pipe nipple with 2 inch external thread x 2 inch external thread and a length of 1000 mm.
Shape matched to the pipe layout
The shape depends on its task in the pipe run: make a straight connection, change direction, create a branch, form a wall connection or close a connection.
Straight connection fittings
Double nipples and pipe nipples provide straight connections with external threads. Couplings and socket nipples are named as separate shapes and complement the selection between internal and external threads.
Direction and wall
Elbows and bends are marked as 45° or 90°. Wall plates and wall elbows also carry a 90° specification and combine the shape with a wall connection.
Branch and termination
Tees, crosses and angle distributors divide a pipe run. Plugs, caps, locknuts and unions are used for termination or detachable connections.
Reading internal threads, external threads and transitions
AG stands for external thread in the product names, while IG stands for internal thread. The order before and after the x describes the two connection ends. The same nominal size at both ends is different from a transition between two sizes.
AG x AG
Both connections have external threads, for example on the brass double nipple 1 inch AG x 1 inch AG or the pipe nipple 2 inch AG x 2 inch AG.
IG x IG
Both ends have internal threads, for example on the malleable iron wall plate 3/4 inch IG x 3/4 inch IG.
IG x AG or AG x IG
Mixed connection ends join different mating parts. One example is the brass double nipple 1/2 inch AG x 3/4 inch IG.
Comparing connection size and length
The product data described includes, among others, 1/2, 3/4, 1, 1 1/2 and 2 inch. Transitions are specified as 3/4 x 3/8 inch, 2 inch AG x 1 inch IG or 1 1/2 x 1 inch. Pipe nipples also come in lengths such as 80 mm, 500 mm and 1000 mm. These values belong to the item named and must be read together with AG or IG.
For a specific selection, the combination of shape and connection ends is important. A 90° elbow with IG x AG routes a pipe differently from a straight double nipple with AG x AG; a reducing fitting also states two different sizes. This lets you check shape and thread separately.
Areas of use in the product data
The descriptions name different technical settings. Brass fittings are associated with plumbing, heating, air conditioning, solar technology and cold and hot water. For stainless-steel fittings, plumbing installation, water technology and heating are the main areas. The data for malleable-iron products names plumbing, heating and gas installations as well as industrial plant construction. Pipe nipples are described as connection parts for liquids and gases.
Installation and sealing of the threaded connection
Before installation, the mating part, connection end and size must match. The AG or IG designation clarifies the thread direction; the shape determines whether a straight section, elbow, branch or termination is needed.
The pipe nipples and malleable-iron angle distributors described are stated to have non-self-sealing threaded connections. The product data names PTFE tape or hemp as sealing materials. This detail belongs to installation planning and is separate from material, shape and connection size.
Checklist for assembling a system
Before assembling a pipe run, note the connection ends of the adjacent parts. Then check the material and shape. For a transition, both thread sizes appear in the product name; for a pipe nipple, length is added. This sequence separates the technical questions and makes the selection in the shopping cart transparent.
Plan the connection
Record a straight section, elbow, branch or wall connection as the required shape.
Compare the details
Consider material, AG or IG, size and, for pipe nipples, length together.
Subcategories by material
The three subcategories organize the material selection before shape and thread size are compared.
Stainless steel 316 threaded fittings
Material group with a stainless-steel 316 designation and thread-based shapes.
Brass threaded fittings
Brass variants with double nipples, elbows, tees and transitions.
Malleable iron threaded fittings
Malleable-iron variants with bends, distributors, couplings, crosses and plugs.
Adjacent areas for planning
Depending on the pipe layout, adjacent categories can provide the next selection point:
Fittings + PE pipe unions
For connections involving PE pipes and unions.
Ball valves, socket gate valves, shut-off valves
Adjacent area for components used to shut off a line.
IBC accessories + tank feedthroughs
Further area for container and tank feedthroughs.
Measurement, regulation & filtration
Adjacent area for measuring, regulating and filtering in the system.
Examples from the range
The product cards show how material, shape, connection size and weight appear together in the respective data.
Brass double nipple
1 inch AG x 1 inch AG · CW617N brass · 0.06 kg.
Galvanized pipe nipple
2 inch AG x 2 inch AG · 1000 mm · 1.2 kg.
Brass tee
1 inch internal thread · 0.15 kg.
FAQ about threaded fittings
The most common selection questions can be answered using the names and product data.
What do AG and IG mean?
AG means external thread and IG means internal thread. The details before and after the x identify the two connection ends. This distinguishes AG x AG, IG x IG and mixed designs.
When is a reducing fitting suitable?
A reducing fitting or reducing nipple represents a transition between different thread sizes in the product data, such as 2 inch AG x 1 inch IG or 1 1/2 x 1 inch.
Which shape changes direction?
Elbows and bends are specified as 45° or 90°. Wall plates and wall elbows also carry an angle specification, while tees and crosses represent branches.
Which lengths are available for pipe nipples?
The described data includes 80 mm, 500 mm and 1000 mm. The length is considered together with the material, thread size and connection end of the respective pipe nipple.
How is a thread sealed?
The product data indicates that the threaded connections of the pipe nipples and malleable-iron angle distributors described are not self-sealing. PTFE tape or hemp is named for sealing.
Which subcategory belongs to which material?
Stainless steel 316, brass and malleable iron have their own subcategories. The subcategory narrows down the material; shape and connection size are then read from the relevant item.