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Clamp Force / Tonnage Screening Estimate

Screen press tonnage from projected mold area, cavity pressure, and the engineering margin you choose.

Example starting values are prefilled to demonstrate the calculation. Replace them with your measured, quoted, or job-specific inputs before relying on a result.

Inputs

Clamp-force screening inputs

Range: at least 0.0 in²

Use the pressure-loaded projected area on the parting plane. Include all active cavities and the runner/sprue/gate projection that contributes to separating force; do not use only one cavity unless the tool has one cavity.

Range: at least 0.0 psi

Enter a validated average pressure for the material, geometry, fill/pack condition, or simulation basis. Do not substitute machine hydraulic pressure or a generic maximum without documenting the source.

Range: at least 1

User-selected design margin. No single universal ASTM/SPI value is applied here; document the basis used by your organization or machine supplier.

Result

Base separating force (lbf)
400,000
Base clamp tonnage before margin (US short tons)
200.00
Screening clamp tonnage with margin (US short tons)
220.00
Engineering limitation
Base separating force = projected melt area × entered average cavity pressure. Screening tonnage = base force × user-entered engineering margin ÷ 2,000 lbf/US short ton. This estimate does not confirm mold deflection, tie-bar loading, machine platen limits, injection pressure, or process capability; review the pressure basis and candidate press with qualified engineering.

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