Deep Drawing Blank Sizing & Draw Reduction Calculator
Calculate cylindrical shell flat blank diameter (D), draw ratio (m), limiting draw reduction (LDR), punch drawing tonnage, and blankholder clamping pressure.
1. Cup & Tooling Dimensions
2. Sizing & Tonnage Output
3. Sectional Forming Visualizer
Tooling & Vector DXF Prepress Notes
1. Surface Area Conservation Rule: For cylindrical cups, flat blank diameter is calculated via $D = \sqrt{d^2 + 4dh - 0.86 r_c d}$. An additional $3\% - 5\%$ trim allowance margin is typically added for final post-draw edge shear trimming.
2. Limiting Draw Ratio (LDR): First-stage draw operations cannot exceed maximum reduction limits (typically $45\% - 50\%$ or $m \ge 0.50$). If required cup depth causes $m < m_{ ext{limit}}$, a multi-stage redraw schedule (e.g. 1st draw $m_1 = 0.55$, 2nd draw $m_2 = 0.75$) is required with intermediate annealing.
3. Die Clearance & Corner Radius: Die entry radius $r_d$ should be $(4-8) imes t$. Clearance between punch and die should be $1.07 imes t$ to $1.15 imes t$ to allow uniform material thickening at the cup mouth without ironing friction.