Bend Allowance and Spring Back in Sheet Metal

The video tutorial explains how to calculate sheet metal bend allowance and setback using standard formulas and charts. It covers the deformation and stretching of metal during bending, the need for bend allowance, and how to develop a flat pattern. The tutorial provides a formula for calculating bend allowance, including an example calculation. It also discusses the spring back effect, which requires over-bending to achieve the desired bend radius and angle.

What is the primary purpose of calculating bend allowance in sheet metal bending?

• To increase the thickness of the metal

• To determine the amount of material to add for a flat pattern

• To change the color of the metal

• To reduce the weight of the metal

What happens to sheet metal when it is bent?

• It becomes thinner

• It becomes heavier

• It deforms and stretches

• It changes color

Why is it necessary to make a deduction from the desired part size when developing a flat pattern?

• To reduce the cost of materials

• To achieve the correct flat size

• To ensure the part fits in a smaller space

• To account for material shrinkage

How is bend allowance defined in the context of sheet metal bending?

• The material removed to reduce weight

• The angle at which the metal is bent

• The thickness of the metal

• The material added to leg lengths for a flat pattern

Which of the following is a key element in the bend allowance formula?

• Weight of the metal

• K factor

• Temperature of the environment

• Color of the metal

In the example calculation, what is the internal radius used?

• 4

• 2

• 1

• 3

What causes the sheet metal to spring back after bending?

• Residual stresses

• Increased temperature

• Decreased pressure

• Material color change

What is the spring back factor used to determine?

• The weight of the metal

• The ratio of final to initial bend angle

• The color change in the metal

• The thickness of the metal