CGCADGuide.tools
Free Engineering Utility

Sheet Metal K-Factor & Bend Calculator

Calculate bend allowance, deduction, setback, and flat blank length based on DIN 6935 standards. Visualize the shifting neutral axis dynamically in real-time.

Presets & Bending Templates

Bending Parameters

Adjust sliders or input exact values to update calculations instantly.

Sheet Thickness (T)
mm
Inside Radius (R)
mm
Bending Angle (Deflection)
°
Flange 1 (L1)
mm
Flange 2 (L2)
mm
Auto is DIN 6935
Manual K-Factor Value

Bending Profile Visualizer

R=2.0T=2.0Blue: Sheet BoundariesRed: Neutral Axis (K=0.44)

Calculated Results

Flat Pattern Blank Length (L)
96.524 mm

Formula: F1 + F2 - BD (Legs - Bend Deduction)

Bend Allowance (BA)
4.524 mm
Bend Deduction (BD)
3.476 mm
Outside Setback (OS)
4.000 mm

Bending Engineering Reference

1. Core Bending Equations

Bend Allowance (BA) measures the length of the neutral axis within the bend area. It represents the material added:BA = (Angle_Rad) * (R + K * T)

Outside Setback (OS) is the distance from the tangent point of the bend to the apex of the mold corner:OS = tan(Angle / 2) * (R + T)

Bend Deduction (BD) is the difference between outside lengths and flat pattern length, subtracting excess material:BD = 2 * OS - BA

2. Real-Time Math Log

// Conversion to radians
90° = 1.5708 rad
// Bend Allowance Calculation
BA = 1.5708 * (2.0 + 0.44 * 2.0) = 4.524 mm
// Setback & Deduction
OS = tan(45°) * (2.0 + 2.0) = 4.000 mm
BD = 2 * 4.000 - 4.524 = 3.476 mm
// Flat Pattern Output
L = 50 + 50 - 3.476 = 96.524 mm