2 wooden or metal form blocks Block of hardwood and heavy-duty hammer or mallet (optional) Calculator or online bend calculator Marker Protractor Rubber, plastic, or rawhide mallet Ruler or tape measure Sheet metal Vise
If your sheet metal is too thick, you may need special machinery, like a brake or a torch, to bend your sheet into the desired shape.
To ascertain your K-Factor, inside radius, and material thickness (expressed as a decimal), you should use an Bend Allowance Chart. As an example, if you want to bend 24 gauge sheet metal at a 90° angle, the calculation would be: 0. 017453 x 90 x (0. 020 + 0. 33 x 0. 024) = 0. 0438558984 inch bend allowance Keep in mind that some metals are more brittle than others. Bending a brittle metal beyond its limits could cause the metal to snap and break. [4] X Research source
One edge of your form will typically be rounded to the degree of your bend radius, thus helping you achieve your desired bend. [7] X Research source
Consider having a friend or a colleague stabilize this piece with their hand. Be sure to wear gloves to prevent any accidental cuts.
Your tapping should start at one end of the evolving bend. Slowly work back and forth between your bend lines until the sheet metal is bent to the desired angle.
For example: if your desire bend is 45°, you will subtract this number from 180°, which will give you a bend angle of 135°. [11] X Research source
Keep in mind that many kinds of fabricated metal have extremely high melting points, and applying your torch injudiciously could cause damage or do harm to your sheet metal or equipment.
