The principle consists in shaping the end of the copper tube to produce a flat flange which will keep the nut, the seal and the threaded portion of the coupling to be tight and tight. This technique is used to connect a hose, supply a sanitary appliance, ensure a connection between two pipes. To make a flared collar, you need the die and the conical top.
Slide the nut onto the tube;
heat the end of the tube to anneal it and make it malleable.
Place the tube in the die on the chamfered side allowing it to protrude 2 to 3 mm.
Close the die and tighten the router firmly to deform the end of the tube.
Release the tube from the matrix. At its exit, the tube must be widely flared on its end.
Turn the die over, then replace the tube in the right-sided hole and hammer to flatten the flare.
The beaten collar is completed;
The tube can be connected with a screw connection and a seal.
If you do not have a matrix to beat a beaten collar, you can also solder fittings already shaped on your tubes.