Cold Heading Wire Cutoff & Fastener Upset Ratio Calculator
Calculate fastener heading upset ratio (U = L_upset / D_wire), total raw wire blank cutoff length, and forming blow tonnage for 1-die-2-blow and progressive multi-station headers.
1. Input Parameters
2. Calculation Results
3. Geometric Visualizer
Tooling & Vector Prepress Engineering Notes
1. Upset Ratio Rule of Heading: The heading ratio $U = L_{\text{upset}} / D_{\text{wire}}$ governs buckling stability. Single-blow headers cannot exceed $U \le 2.25$. Two-blow headers handle $U \le 4.5$, while 3+ station multi-die progressive headers form up to $U \le 6.5$.
2. Cone Tooling Pre-Form Angle: In first-blow coning punches, a $12^\circ - 15^\circ$ entry taper centers the wire and prevents off-axis grain flow folds.
3. CNC Die Sinking DXF: Die cavity DXFs must incorporate a $0.03 - 0.05\text{mm}$ wire lead-in radius and $1.5\% - 2.5\%$ elastic die springback expansion allowance.