KEVOS® MAKEOS · Fabrication
Press Tonnage for a Compound or Progressive Die
What total press force does this die need for blanking, piercing, bending and drawing together, and is the press big enough?
Total press load for a compound or progressive die stage by summing the handbook forces for blanking and notching (perimeter × thickness × shear strength), piercing a number of holes, bending (L T² × UTS ÷ die opening) and a first draw (π d T × UTS), plus stripping force and a safety margin, with the cutting energy per stroke and the press capacity check.
Open the calculatorRuns in your browser. No account needed.
How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Material thickness | mm | Sheet thickness. |
| Shear strength | MPa | Shear strength of the sheet (often about 0.8 × tensile strength). |
| Tensile strength | MPa | Ultimate tensile strength. |
| Operations (0 = none) | ||
| Blanking and notching perimeter | mm | Total length cut at once around blanks and notches. |
| Number of holes pierced | Number of holes pierced in the same stroke. | |
| Hole diameter | mm | Diameter of each pierced hole. |
| Length of bends | mm | Total length bent in the stroke. |
| Bend die opening | mm | Opening of the bending die. |
| Mean diameter of a first draw | mm | Mean shell diameter of a first draw in the same stroke. |
| Allowances | ||
| Stripping force (share of cutting force) | % | Force to strip the strip off the punches. |
| Press safety margin | % | Margin above the calculated load when choosing a press. |
| Penetration at fracture (share of thickness) | % | Share of thickness the punch penetrates before fracture (for cutting energy). |
| Press capacity | kN | Rated press capacity. |
Method and formulas
- Blanking and notching: F = perimeter × t × τ; piercing: F = holes × π d × t × τ.
- Bending: F = L t² UTS ÷ W (handbook formula 36); first draw: F = π d t UTS (formula 44).
- Total = cutting forces × (1 + stripping) + bending + drawing; required press = total × (1 + margin).
- Cutting energy ≈ cutting force × thickness × penetration share.
- Example: the default die needs 404.76 kN, or 485.71 kN with margin.
Limitations
- Peak forces assumed to coincide; staggering punch lengths or shear on punches lowers the peak.
- Press capacity is usually rated near the bottom of the stroke.
- Example values are illustrations. Replace them with values for your actual task.
Typical uses
- Choose a press for a new die
- Check a progressive die against press capacity
- Estimate cutting energy for a flywheel press
Who it is for
- Toolmakers
- Press shop engineers
- Estimators
What you get
- Force for each operation
- Total and required press force
- Cutting energy and capacity check
Interpreting the result
- Check the press rating at the point in the stroke where the peak occurs, not just its nominal tonnage.
References
- Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 1336–1359, 1386–1392. Topic reference; no source tables or recommended settings are reproduced.
WORKOS tools are screening and decision-support utilities. Verify important financial, engineering, safety, legal or operational decisions using appropriate professional standards and your organisation’s approved data.
Open the Press Tonnage for a Compound or Progressive Die calculator
