How to Calculate Bend Allowance in SolidWorks: Step-by-Step Guide
In SolidWorks, calculate
bend allowance by using the formula BA = (π/180) × Bend Angle × (Radius + K-Factor × Thickness) or use the built-in sheet metal tools that automatically compute it based on material and bend parameters. The K-Factor represents the neutral axis position and is key for accurate results.Syntax
The bend allowance formula in SolidWorks is:
BA = (π/180) × Bend Angle × (Radius + K-Factor × Thickness)
Where:
- BA = Bend Allowance (length of the bend arc)
- Bend Angle = angle of the bend in degrees
- Radius = inside bend radius
- K-Factor = ratio locating the neutral axis (usually between 0 and 0.5)
- Thickness = material thickness
DAX
BendAllowance = (PI()/180) * BendAngle * (Radius + KFactor * Thickness)Example
This example calculates bend allowance for a 90° bend with 2 mm radius, 1.5 mm thickness, and a K-Factor of 0.3.
Python
BendAngle = 90 Radius = 2 Thickness = 1.5 KFactor = 0.3 BendAllowance = (3.1416/180) * BendAngle * (Radius + KFactor * Thickness) BendAllowance
Output
4.7124
Common Pitfalls
Common mistakes when calculating bend allowance include:
- Using incorrect K-Factor values; it varies by material and bend method.
- Confusing bend allowance with bend deduction or bend radius.
- Not accounting for material thickness properly.
- Ignoring the bend angle units (must be in degrees).
Always verify parameters and use SolidWorks sheet metal tools for automatic calculation when possible.
Python
/* Wrong: Using K-Factor = 1 (invalid) */ BendAllowanceWrong = (3.1416/180) * 90 * (2 + 1 * 1.5) /* Correct: Using K-Factor = 0.3 */ BendAllowanceCorrect = (3.1416/180) * 90 * (2 + 0.3 * 1.5)
Quick Reference
| Parameter | Description | Typical Values |
|---|---|---|
| Bend Angle | Angle of the bend in degrees | 0° to 180° |
| Radius | Inside bend radius in mm or inches | 1 mm to 10 mm |
| Thickness | Material thickness | 0.5 mm to 5 mm |
| K-Factor | Neutral axis location ratio | 0.3 (common default) |
| Bend Allowance | Length of bend arc | Calculated value |
Key Takeaways
Use the bend allowance formula with correct bend angle, radius, thickness, and K-Factor.
K-Factor is critical and varies by material and bending method; default is often 0.3.
SolidWorks sheet metal tools can automate bend allowance calculation for accuracy.
Always keep bend angle in degrees and verify units for radius and thickness.
Avoid confusing bend allowance with bend deduction or bend radius.