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Edited by IngeborgK, Erin Lucy, Dina Ibrahim, Maluniu and 4 others

Most frequently, sheet metal brakes are used to bend sheet metal, but you can also complete this task without a brake. Bending sheet metal by hand is a manageable task if the piece of sheet metal is small and thin enough to handle. Learn how to bend sheet metal so you can complete home and hobby projects easily without using a sheet metal brake.



  1. Bend Sheet Metal Step 1.jpg
    Obtain all the required materials to complete the job.
  2. Bend Sheet Metal Step 2.jpg
    Use a tape measure or ruler to measure the thickness of the sheet metal. Use a protractor, and mark your angle with a marker. This line will be your bend line.
  3. Bend Sheet Metal Step 3.jpg
    Calculate the bend allowance so that you know which angle to mark for a clean bend in your sheet metal. The formula is: (0.0173 x R + 0.0078 x T) x N = bend allowance (BA), where R is the desired bend radius (1 to 180 degrees), T is the thickness of the material, and N is the number of degrees of bend.
  4. Bend Sheet Metal Step 4.jpg
    Clamp the sheet metal along the bend line between 2 form blocks held inside a vise. One edge of the form blocks is typically round to give you the desired bend radius.
  5. Bend Sheet Metal Step 5.jpg
    Use a rubber, plastic, or rawhide mallet to gently tap the metal so that it bends toward the form block to achieve the desired angle gradually and evenly. Start tapping at 1 end of the evolving bend, and slowly work back and forth until the sheet metal is bent all the way across at the desired angle.

Add your own method


  • To remove irregularity or improve uneven bends, place a hardwood piece lengthwise along the bend and hit the bend with increased strength using a heavy-duty hammer or mallet.
  • If you don't want to bend sheet metal by hand, you can use a sheet metal brake. Manual sheet metal brakes are for hobbyists and small or mobile businesses. Hydraulic, computer controlled sheet metal brakes are used for high-volume industrial or construction use.
  • Using an online bend calculator is easier than using a traditional calculator to determine the bend allowance.
  • If you need to exert a bit more force to get the sheet metal to bend due to increased thickness or size, hold down the protruding side of the sheet metal with your hand while you use a mallet to bend it. This will prevent the metal from bouncing.


  • Make sure you have correctly solved the bend allowance equation before attempting to bend sheet metal. If the equation is solved incorrectly, your sheet metal bend will be incorrect and ruin your project.

Things You'll Need

  • Sheet metal
  • Ruler or tape measure
  • Protractor
  • Marker
  • 2 wooden or metal form blocks
  • Vise
  • Rubber, plastic, or rawhide mallet
  • Calculator or online bend calculator
  • Block of hardwood and heavy-duty hammer or mallet (optional)

Article Info

Categories: Metalwork and Wire Projects

Recent edits by: Sddek, Mel, BR

In other languages:

Español: Cómo doblar una hoja de metal, Português: Como Dobrar uma Folha de Metal


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