Powder Metallurgy & Sintered Parts worked example

Shrinkage Allowance with green dimension of 63 units: a worked example in powder metallurgy & sintered parts

Here is what the math looks like when conditions slip. We hold every other input steady and drop green dimension to 63 units, then walk the calculation through step by step. Shrinkage allowance is the dimensional gap a powder metallurgy part loses (or, for some alloys, gains) as it densifies during sintering, and it is the number that decides how big the compaction die and core rods must be cut.

The inputs for this scenario

  • Green (as-pressed) dimension: 63 units (the input this scenario stresses; the baseline uses 125)
  • Sintered (final) target dimension: 100 units (held at the documented default)
  • Reference dimension for percentage: 100 units (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Shrinkage Allowance margin = available value - required value.
  • Margin works out to -37 % at these inputs, and this is the headline figure for the scenario.
  • Absolute margin works out to -37 value at these inputs.
  • Available amount works out to 63 value at these inputs.
  • Required amount works out to 100 value at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where green dimension sits at 125 units and the headline result is 25 %, this scenario comes in 248% below the baseline at -37 %.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to green dimension, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It assumes uniform, isotropic shrinkage; real PM parts shrink anisotropically (differently in the press direction versus transverse), so a single allowance won't hold for every feature on a complex part.

Results at a glance

  • Margin: -37 % (headline result)
  • Absolute margin: -37 value
  • Available amount: 63 value
  • Required amount: 100 value

Run it with your numbers

  • To rerun this with your own numbers, open the live Shrinkage Allowance calculator, set green dimension to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.