They aren't!
You are thinking of a single bend press brake type of bending metal flanges.
That part is done in a die with maybe 2-4 pressing operations to get the final shape.
"Wildfires are dangerous, hard to control, and economically catastrophic."
As 3DDave indicated, this is a component from a progressive die. You can tell from two short tabs on top. Those are locations of a carrier.
1. Blank;
2. Pre-form to potato chip shape;
3. Pre-bend the flanges;
4. Final forming with pressure pads;
5. Piercing the holes;
6. Trim off the carrier.
The edge of the metal plate on the engine bracket is bent in several ways, depending on the required shape and function.
1. **Manual Bending**: In some cases, workers can manually bend the edge of the metal plate using hand tools such as hammers, clamps, or molds. This method is typically employed for smaller or custom sheet metal fabrication.
2. **Mechanical Bending**: For larger or more complex metal plates, mechanical equipment such as bending machines or rolling machines is often used to apply force and precisely bend the metal. This method can achieve higher precision and consistency.
3. **Heat Forming**: Occasionally, in instances where more intricate shapes are required, heat forming methods such as hot bending or flame heating may be utilized to soften the metal before bending.
4. **Forming Processes**: During metal fabrication, forming processes such as stamping, folding, and molding can also be employed to shape the metal by applying pressure or bending.
The choice of these methods depends on factors such as required precision, complexity, production volume, and material characteristics. The bent edges may be designed in various shapes to meet the structural and functional requirements of the bracket.
