Shop Tricks and Tools
Simple tools and proven methods for better sheet metal control and durability.
Sheet Metal Hand Break
Bending large sections of thin-gauge sheet metal – 16 gauge and thinner – is usually a fairly easy process, but when the pieces get smaller or shorter, creating simple flanges and making 90-degree bends becomes more challenging.
A metal hand break will bend thin sheet metal easily and accurately in most cases, and it’s easy to make. It can be constructed with different sizes and thicknesses of materials, depending on the thickness of metal that you’ll be bending, but for the purposes of this conversation, we’ll focus on thin sheet.
You’ll need two pieces of angle iron – one 3x3 inch and the other 2x2 inch. The thickness of both can be 1/8 inch or 3/16 inch. You’ll also need two pieces of square tubing for the framework, a 6- to 8-inch piece of round tube, and a 2- to 3-foot piece of solid bar for a handle.
Start with the large angle iron and weld the angle to the square tube framework. Weld the square tube on each end of the angle facing up to create a “V” with legs. The second smaller piece of angle will lay inside the larger angle, with the swivel point welded to one end.
Cut the round tube into three sections. Weld one section to the small angle. Weld the other two sections to either side of the large angle to form the pivot point. Use a bolt or piece of round bar to hold the pivot point together. Now the smaller angle will sit inside the larger angle and pivot up and down. Make sure to deburr all the edges and sharp points of the angle. Attach the solid bar handle by welding it inside the smaller angle.
To use the hand break, clamp the framework to your worktable, insert the sheet metal between the angles, and apply pressure by hand to bend the metal. This tool can be easily modified for different sizes and thicknesses of material, but if you have simple bends to make in your sheet metal, it can do the job quickly and easily.
Strengthening Sheet Metal Edges
When fabricating sheet metal, there are different ways to strengthen thin, flimsy material. The weakest parts of a sheet panel are usually the edges. For example, the edges of a motorcycle or car fender are always very flimsy, and usually need strengthening to prevent distortion and cracking of the metal. In addition, primer and paint generally don’t adhere consistently to the edges of sheet metal.
A hemmed edge or wired edge can be effective solutions for these challenges. They can greatly increase the strength of the sheet metal and also provide a better surface for coatings.
Creating a hemmed edge involves folding the edge of the sheet metal on top of itself to create a stronger double layer with a rounded edge more suitable for coatings. It was a common technique in the automotive industry many years ago to strengthen the edges of the sheet metal used in the assembly process. A wired edge is very similar to a hemmed edge, but it involves welding a wire to the edge of the sheet metal and sometimes wrapping the metal around the wire. The wired edge technique is used for 16-gauge metal or thinner.
You’ll need a dolly and a body hammer for either technique. To create the hemmed edge, measure about ½ inch from the edge of the metal. Use the hammer to create a slight bend along the entire length of the metal at the 1/2-inch mark. Repeat the process, bending more each time until the 1/2-inch edge is fully folded back onto itself. At some point during the bending process, the dolly will get in the way of the fold. When this happens, reposition the dolly to the opposite side of the metal so you can hammer from there.
To create the wired edge, position a length of 1/8-inch wire about 1/8 inch to 1/4 inch from the edge of the metal. The initial bend will help hold the wire in place, and a few tack welds can be helpful here (but they are not absolutely necessary).
Regardless of which type of edge you’re creating – hemmed or wired – begin the hammering process on the line of the actual bend and work your way outward toward the edge of the metal in a smooth and controlled manner to avoid wrinkling the metal. If you simply hammer the edge of the metal to bend it without following the bend line, the material will not bend at the point where you want it to – which will likely result in some rework (and some frustration). When completed you will see the difference in the strength of the sheet metal edge.
Remember to take your time and maintain a light touch. It’s only sheet metal, so leave the ball peen and sledge hammers in the tool box.