The Sheet Metal K-Factor, Bend Allowance & Blank Flat Pattern Sizer provides an interactive three-parameter algebraic tool for exploring press brake bending geometry, neutral axis displacement, and flat blank layout proportions.

### Algebraic Ratio Formulation The component evaluates metal forming parameters using three generalized algebraic equations: - Primary Metric: $(val_1 \times val_2) / \max(0.01, val_3)$. In sheet metal bending, this models developed bend length scaled relative to bend angle and material deformation resistance. - Geometric Mean (Secondary Index): $\sqrt{\max(0, val_1 \times val_2)}$, modeling geometric mean bend radius and stock thickness dimensions. - Efficiency Ratio (%): $\min(100, \max(0, (val_1 / (val_1 + val_2)) \times 100))$, modeling neutral axis location ratio relative to outer fiber elongation.

### Note on Sheet Metal Forming Mechanics & K-Factor Formulas This tool computes a generalized three-variable algebraic proxy. In precision sheet metal fabrication and CNC press brake programming, true flat pattern blank lengths require exact empirical bend calculations: - K-Factor: $K = \frac{t}{T}$, where $t$ is distance from inside bend face to the neutral axis and $T$ is total material thickness (typically $0.33$ for soft air bending up to $0.50$ for bottoming/coining) - Bend Allowance ($BA$): $$BA = \frac{\pi}{180} \times A \times (R + K \times T)$$ where $A$ is bend angle in degrees and $R$ is inside bend radius - Bend Deduction ($BD$): $$BD = 2 (R + T) \tan\left(\frac{A}{2}\right) - BA$$ - Total Flat Blank Length: Sum of outside flange lengths minus bend deductions ($L_{\text{flat}} = \text{Flange}_1 + \text{Flange}_2 - BD$).

### Worked Numeric Example Using default component parameter values: - Primary Dimension / Load ($val_1$): 100 - Operating Coefficient ($val_2$): 20 - Safety Factor / Loss Ratio ($val_3$): 5 - Evaluated Outputs: - Primary Metric: $(100 \times 20) / 5 = 400.00$ - Geometric Mean: $\sqrt{100 \times 20} = \sqrt{2000} \approx 44.72$ - Efficiency Ratio: $(100 / (100 + 20)) \times 100 = 83.33\%$

### Client-Side Processing Note All sheet metal calculations execute strictly inside your local web browser with zero telemetry or server data transfer.