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Copper Tube Swaging and Deburring Tools!

Updated: Nov 20, 2023

Swaging tools are used to expand the end of a copper tube to accept the next section of tubing. This is done prior to making a permanent braze or solder connection. Swaging is a method used on ACR (Air Conditioning, Refrigeration) copper tubing for refrigerant as well as soft copper tubing used for plumbing. Swaging is done to reduce the amount of brazed or soldered joints in a tubing run. In the case of a coupling, two braze joints are needed, whereas with a swage, only one braze joint is needed. Both swaging and deburring tools are examined in this article.

The 5 major swaging tools used in the field are as follows:

  • Manual Swage

  • Hydraulic Swage

  • Standard Flare and Swage Kit with Block

  • Spin Swage

  • Hammer Swage

The 3 major deburring tools used in the field are as follows:

  • Deburring Pen

  • Uni-Bit

  • Round Deburring Wheel

Cutting and Deburring tubing

A deburring pen, unibit, or round deburring wheel are tools that can be used to deburr copper tubing prior to swaging.

  • Use a tubing cutter to cut the tube to the correct size. Notice how after being cut, the tubing end is very sharp and indented inward (see photo below).

  • Whenever you deburr a tube, make sure the shards that you’ve cut from the tube are cleared out of the copper tube.

  • If you are deburring line set, hold the end of the tube at a downward angle so the shards fall out of, and not into, the line set.

Types of Deburring Tools

#1 Deburring Pen

  • A deburring pen is also known as a deburring stick or even as a stick reamer. This is used to smooth the end of tube by cutting along the inside rim of the tube. This is done by moving the deburring pen in a circular manner.

  • Deburring pens come in different styles and with different size handles.

#2 Unibit

  • A unibit attached in a drill is a fast way to deburr tubing.

  • Keep your fingers away from both ends of the tube as well as the unibit to avoid any hazards before/while spinning the unibit with the drill.

  • Hold the tube in the middle and to avoid injury.

  • A unibit is an excellent tool to use when deburring a large quantity of tubing.

#3 Round Deburring WheeL

  • A round deburring wheel (also known as a round reamer) is a basic tool with three internal blades that is rotated back and forth on the end of the copper tube.

  • It is easy to grip and manually rotate.

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Types of Swaging tools

#1 Manual Swage

  • Screw the correct size die onto the manual swaging tool (see photo below).

  • Place the tube onto the die (see photo below).

  • Pull the two handles toward eachother about halfway then slightly rotate the copper tubing before pulling the handles together all the way. Do this to compensate for the small seams in the die. This is to avoid any cracking of the tube at the stretched copper tube locations.

  • The pic below shows the seams between the die sections when the handles are together.

  • Don’t force the swage at the end of procedure, as you may accidentally open up the tube end too much. The result will be slop between the two tubes which will need to be filled in while brazing or silver soldering. The ideal scenario is to get a snug fit with the swage of the first tube over the second tube.

#2 Hydraulic Swage

  • The die attaches to the tool with about a ¼ turn. Some models require that the die is screwed on.

  • The premise of this tool is similar to the manual swaging tool, except you pump/squeeze the handle to make the die expand in order to swage the copper tubing.

  • Similar to the manual swage, halfway through the swaging process stop and rotate the copper tube. This is done to avoid cracking the tebe at the stretch spots.

  • Stop swaging after the squeezing action becomes harder to perform. Don’t force the swage at the end of procedure, as you may accidentally open up the tube end too much.

#3 Standard Flare and Swage Block

  • Depending on the pipe diameter, mount the appropriate size swage die onto the head of the tool.

  • Make sure the correct length of the tubing extends out from the block. This should include a distance to accept the swage die and the smaller end of the swage die (see photo below).

  • Tighten the tubing into the block using the wing nuts. Mount the handle assembly onto the block (see photo below). Do not overtighten the wing nuts or the tubing will be squished where it is being held in the block.

  • Turn the handle rod clockwise to make the swage. Do this until it is visually seen that the swage is complete (see photo below).

  • NOTE: This tool requires a little more effort than most of the other swaging tools.

#4 Spin Swage

  • Wear thick gloves when using a spin swage in order to protect your hand from the heat generated by the spinning tool. Hold firmly on the tubing so that the tube does not spin.

  • Use a high torque and high rpm drill to rotate the spin swage. While the drill is spinning at a high rpm, push the spin swage into the copper tube. The heat generated due to friction is what allows the spin swage to enter the tubing in order to expand it (see photos below).

  • A spin swage prepares the inside of the tube for brazing by leaving it clean and smooth.

  • It is important to hold the drill as straight as possible. Otherwise, you’ll get slop (not a snug fit between the two tubes).

  • Copper dust/debris can enter the tube if you spin the swage for too long in the tube, and/or if the tube end that is being swaged is not pointing down towards the ground. Make sure not to get dust within the tube when working with refrigerant because this will get trapped within the tube and continually circulate through the tubing as the air conditioning system runs.

#5 Hammer Swage

  • Always wear gloves when using a hammer swage, as you have to hold onto both the tube and swage as you are hammering (see photos below).

  • If needed, a standard flare and swage block can be used to hold the tube. This is to ensure that all the force of the hammer goes into the copper tube.

  • Insert the correct size hammer swage into the tube. Firmly, hammer the end of the swage into the tube as straight as possible (see photo below).

  • Stop once the entire front part of the swage is inside the tube (see photo below).

Published: 07/13/2022

Author: Craig Migliaccio

About the Author: Craig is the owner of AC Service Tech LLC and the Author of the book “Refrigerant Charging and Service Procedures for Air Conditioning”. Craig is a licensed Teacher of HVACR, Sheet Metal, and Building Maintenance in the State of New Jersey of the USA. He is also an HVACR Contracting Business owner of 17 years and holds an NJ HVACR Master License. Craig creates educational HVACR articles and videos which are posted at &

1 comment

1 Comment

Brendan Conley
Brendan Conley
Jul 13, 2022

You forgot about the reamer that is on a lot of tubing cutters, I use mine all the time because it's right there after I cut the tubing. Also if you use a hammer swag I recommend clamping the tube in a flaring block about a 1/4"-1/2" an inch down it will help keep the end straight.

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