Stainless steel tubing is strong, lightweight and usually easy to work with. However, when you need to flare a tube, you need the right equipment. Flaring widens the end of a tube to increase its diameter. Flaring tools and tube clamp bars can be bought or rented from a plumbing supply store. The flaring tool uses a cone-shaped piece of metal that goes into the tube and a round, flare-shaped clamp that surrounds the end of the tube. When the cone is screwed into the tube, it forces the steel to take on the shape of the flare.
Insert the tubing into the flaring tool's clamp bar.
Insert the clamp bar into a vice and tighten the vice firmly.
Cut your stainless steel tubing to length with a hacksaw, as close to the clamp bar as possible. Use light pressure with even strokes to make sure you do not bend the tube while cutting. Use as little pressure as possible as you approach the end of the cut or you may damage the tube. Best results will come from a blade with 32 teeth per inch or more.
File off any tangs left on the steel after your cut. Then gently file down the tube until it is smooth and square. Filing the tube until it is flush with the clamp bar is the best way to ensure the cut is square.
Remove the clamp bar and tube from the vice.
File the outside edge of your cut to remove the burrs, holding the tube at a 30-degree angle to the file and rotating the tube slowly as you file.
File the inside edge of the cut by placing the corner of your file inside the tube. Slowly rotate the inside of the tube against the file.
Insert the end of the tube into the flaring tool, with the end flush with the flared end of the hole.
Place the flaring tool head on the block according to the manufacturer's instructions. Ensure the flaring cone on the head has been centered.
Screw down the cone into the pipe. The cone will force the steel tube to the shape of the flared hole.
Remove the pipe from the flaring tool and examine the tube to make sure the flare is smooth and round.
