How do you connect two steel pipes without welding?

Connecting steel pipes without welding requires considering factors such as pipe thickness, diameter, and intended use. Depending on these variables, various methods and fittings can be employed to achieve a secure and reliable connection.

This web post explores different options for connecting steel pipes, taking into account the pipe type and applications. Read on to discover the suitable techniques and fittings for your specific requirements.

Thick-Walled Pipes:
For thick-walled steel pipes, threading and using a union or a threaded joiner are recommended methods. These fittings enable a strong connection between the pipes, ensuring structural integrity.

Thin-Walled Pipes:
When dealing with thin-walled pipes, the connection method depends on whether the pipes have the same diameter or if one can fit into the other.

Equal Diameter Pipes:
If the thin-walled pipes have the same diameter, several approaches can be employed. Swaging one pipe to fit into the other or stretching one pipe to fit over the other are viable options. Once the pipes are concentrically fitted, you can choose from methods such as soldering, brazing, using a sealer compound with a “U” bolt clamp, threading with a coupler, taping, or gluing. The choice depends on the desired strength of the joint.

Different Diameter Pipes:
If the thin-walled pipes have different diameters, soldering, brazing, or using a sealer compound in conjunction with a “U” bolt clamp are suitable methods. These techniques ensure a secure connection between the pipes.

Additional Connection Options

Apart from the methods mentioned above, there are several other fittings available for connecting steel pipes based on your needs:

  1. Threaded Female Couplings: These couplings allow for threaded connections between steel pipes, ensuring a tight and reliable joint.
  2. Grooved Clamshell-Type Fittings: Fittings like Victaulic-style grooved clamshell fittings provide a convenient and efficient way to connect steel pipes. These fittings feature a grooved design that simplifies the connection process.
  3. Push-to-Connect Couplings with O-Rings: Push-to-connect couplings equipped with O-rings offer a quick and easy connection solution. They eliminate the need for threading or soldering and provide a leak-resistant joint.
  4. Flanged Fittings: Flanged fittings are commonly used for connecting steel pipes in industrial applications. The flanges provide a strong and secure connection, suitable for high-pressure environments.


When it comes to connecting steel pipes without welding, considering the pipe type, thickness, diameter, and intended use is essential. Depending on these factors, you can choose from various methods such as threading, swaging, stretching, soldering, brazing, or using different fittings like threaded couplings, grooved clamshell-type fittings, push-to-connect couplings, or flanged fittings.