Precision Tube & Bar Forming

Rotary Swaging & Radial Forging Tube Reduction Calculator

Engineering tooling calculator for rotary swaging, radial forging, and cold tube pointing. Computes outer diameter reduction, cross-section area reduction percentage, axial elongation ($L_1 = L_0 \frac{A_0}{A_1}$), die taper entrance length, and wall thickening behavior.

1. Input Parameters

Initial Tube Outer Diameter D0 (mm)

Initial Wall Thickness t0 (mm)

Target Reduced Outer Diameter D1 (mm)

Initial Blank Tube Length L0 (mm)

Die Entrance Taper Angle α (deg)

Half-angle of die reduction cone (typically 5° - 12°)

Internal Mandrel Process Type

2. Calculation Results

Area Reduction Ratio

-- %

Final Swaged Length L1

-- mm

Final Wall Thickness t1

-- mm

Die Taper Axial Length

-- mm

Calibration Land Length

-- mm

Rec. Axial Feed Speed

-- mm/s

3. Geometric Visualizer

Tooling & Vector Prepress Engineering Notes

Rotary Swaging Kinematics & Forging Blows: Rotary swaging reduces solid bars and hollow tubes through thousands of rapid, radial high-frequency forging impacts (1,000–3,000 blows/min) delivered by segmented tool steel dies driven by spindle rollers. Cold swaging improves tensile strength via strain hardening, achieves mirror surface finishes ($Ra < 0.2\,\mu\text{m}$), and tight diametrical tolerances ($\pm 0.02\,\text{mm}$).

Wall Thickening & Volume Constancy: In free tube sinking (without an internal mandrel), reduction of outer diameter forces material inward, thickening the wall by approximately $t_1 \approx t_0 \sqrt{D_0 / D_1}$. Using an internal mandrel constrains the inner diameter, resulting in thinner, uniform walls and greater axial elongation ($L_1 = L_0 \cdot A_0 / A_1$).

Die Profile CAD/CAM Vectors: Swaging die inserts consist of three zones: (1) Entrance radius ($R \ge 2\text{mm}$), (2) Reduction cone angle ($\alpha = 5^\circ - 12^\circ$), and (3) Sizing calibration land ($L_{\text{land}} = 0.8 - 1.5 \times D_1$). These profile lines must be generated with continuous $G^2$ curvature transitions in wire EDM or CNC turning DXF toolpaths.