Project Guide

How to Use Swaging and Flaring Tools for Copper Pipe and Tubing

What are Flaring Tools?
A person places tubing in a heavy-duty flaring tool.
  • Flaring tools use pressure to make a fabricated mechanical joint for joining or sealing copper tubing with a flare connection. Flaring allows you to connect tubes to each other or another kind of fitting. 
  • Flared ends tend to have an approximately conical shape. 
  • The most popular flaring tool for copper tubing is the bar-type tool, which include multiple bits to accommodate different pipe or tube sizes. 
  • Tubing and piping flares are not interchangeable. Tubing flares have a 45-degree angle while piping flares have a 37-degree angle. 
What are Swaging Tools?
A punch swager tool on a table.
  • Swaging tools use pressure to expand or stretch the end of a piece of copper tubing so it can fit over another of the same diameter and make a permanent brazed connection. Tube swaging seeks to increase the inside diameter of tubing, eliminate the need for additional fittings (which can potentially save money) and reduce the opportunity for leaks. 
  • Swaged ends tend to have a cylindrical shape. 
  • The types of swaging tools for copper pipe include spike-shaped punch tools, manual tube expanders and feed screw tools comparable to flaring bars. 
  • Often a flaring tool kit will come with swaging bits or die blocks to convert a flaring bar into a swaging bar. 
Preparing the Copper Tubing
A person cleans the end of copper tubing with a deburring tool.

Before using flaring and swaging tools, prepare the length of copper pipe or tubing to be shaped. 

Place the Tubing in the Flaring Tool
A person places copper tubing in a flaring tool.
  • When flaring, begin by choosing the tool accessories that match the diameter of the tube to be flared. 
  • Place the tubing inside the die block or clamp of the flaring tool. The end of the tube should extend about 1/8 inch (about the height of a nickel) from the flaring tool. 
  • Tighten the wing nuts to secure the tubing in the tool. 

Tip: Place a drop of oil on the flaring cone to smooth the process. 

Flaring the Tube
A person flares the end of copper tubing in a flaring tool.
  • Center the flaring cone over the tubing. 
  • Tighten the flaring tool to lower the press into the tubing until it forms a flare. Do not over-tighten, which risks splitting the copper. 
  • Loosen and remove the flared tubing. 

Tip: If you have a kit with swaging accessories and want to swage a tube, follow the same steps, replacing swaging bits for the flaring bits. 

Swaging With a Punch Tool
A hammer drives a punch swager into the end of copper tubing.

A punch swager is among the simplest and least expensive tools available for swaging. 

  • Secure the tube in a vise or hold by hand in a firm grip.
  • Matching the diameter of the tube to the appropriately sized punch, put the narrow end inside the tube. Make sure that it’s aligned perfectly straight. 
  • Strike the end of the punch with a hammer until the tube meets the stop. 
Swaging with a Tube Expander
A tube expander kit.

 A tube expander makes it easy to swage tubing of different sizes. 

  • Attach an expander head that matches the diameter of the tube to the end of the tool. 
  • Fit the head into the end of the tube and gradually squeeze the handles. 
  • Release when the end of the tube is fully swaged. 

Learning how to use a swaging tool or a flaring tool is effective for shaping a relatively soft metal such as copper, and can give you more control over your home plumbing and other projects.