What is the purpose of bend allowance?
Bend allowance calculations are used to determine the developed length of flat sheet metal required to make a bend with a specific radius and angle. These calculations are important to create an accurate flattened model for manufacture.
How do you calculate bend allowance?
To calculate bend allowance:
- Obtain the properties of the bend (bend radius, angle, and method used).
- Obtain the characteristics of your material (thickness and K-factor for this specific bend).
- Input everything into the bend allowance formula: BA = angle × (π/180) × (radius + K-factor × thickness) .
What is bend allowance K factor?
K factor is a ratio between the distance from the neutral bend line to the inside bend radius and the material thickness. K factor uses the formula K factor = δ/T.
What is Airbend?
Air bending is a bending process that involves the use of a punch brake to bend sheet metal. Once positioned inside the punch press, the top die presses down and into the bottom die. Because the sheet metal is positioned between these two dies, it bends to form the shape of the dies.
What is an example of bending?
For example, a closet rod sagging under the weight of clothes on clothes hangers is an example of a beam experiencing bending.
Is bend allowance the same as K factor?
The K factor is defined as the ratio between the material thickness (T) and the neutral fibre axis (t), i.e. the part of the material that bends without being compressed nor elongated. Bend allowance is a fundamental parameter to calculate sheet elongation.
How is bend allowance and bend deduction calculated?
Figure 2: Every bend has two outside setbacks (OSSB). So to calculate the bend deduction, multiply the OSSB by 2, and then subtract the bend allowance (BA), which is the length of bend along the neutral axis.
Why do we need to calculate bend allowance and bend deduction?
Considering the Bend Deduction and Bend Allowances is a critical first step in designing sheet metal parts as it affects nearly every following step in the fabrication process. More so, it will allow you to achieve the correct size and dimensions needed in the flat pattern.
What is K-factor solidworks?
K-Factor is a ratio that represents the location of the neutral sheet with respect to the thickness of the sheet metal part. When you select K-Factor as the bend allowance, you can specify a K-Factor bend table. The SOLIDWORKS application also comes with a K-Factor bend table in Microsoft Excel format.
Why do we need K-factor?
K- and Y-factors make metal bending more precise without damaging the material. Once you know the K-factor you can identify the location of the neutral axis after bending in addition to how much the material elongates during bending.
Why do we use K-factor?
The K-Factor is used to calculate flat patterns because it is directly related to how much material is stretched during the bend. It’s used to determine Bend Allowances and Bend Deductions ahead of the first piece.