Press Fit Calculator

Estimate interference pressure, assembly force, and torque capacity.

All tools free forever

Tip: Input shaft/hole diameters to confirm interference.

Results

20
Interference (um)
52.47
Contact pressure (MPa)
27.709
Assembly force (kN)
554.45
Torque capacity (N*m)
Interference fit
Fit status
Linked Parameter Diagram
pressFit

Input / Output Bars

Inputs

Shaft diameter40.02
Hole diameter40
Fit length35
Shaft E210

Outputs

Interference20
Contact pressure52.474
Assembly force27.709
Torque capacity554.454

Geometry View

Press-Fit Section

Shaft Ø
40.02 mm
Hole Ø
40 mm
Fit Length
35 mm
Interference
20 um
Pressure
52.47 MPa
Status
Interference fit
  • Uniform-pressure approximation for planning.

Tool role and boundaries

Press Fit Calculator is not a one-shot number widget. It is an engineering baseline tool for real shop-floor decisions. Estimate interference pressure, assembly force, and torque capacity. This tool supports geometry and fit logic where coordinate definitions and dimensional relationships must stay traceable.

Treat every output as a first-pass candidate, not an immediate production command: run defaults first, tune one variable at a time, and record machine, tooling, fixture, and material-lot context.

Fast baseline workflow

  1. Run once with defaults to confirm units and expected behavior.
  2. Lock constraints first (dimensions, machine limits, setup boundaries), then tune controls.
  3. Change one key variable per iteration and record why it changed.
  4. Check primary outputs against machine capability before secondary metrics.
  5. Validate first piece with conservative override before moving to target cycle.
  6. Store accepted values with revision tags so shift handoff stays reproducible.

Input strategy

Use a three-layer input model:

  • Constraint layer: dimensions, tolerances, travels, clamping, controller limits.
  • Control layer: speed, feed, engagement, compensation, cycle parameters.
  • Target layer: takt time, cost, scrap risk, tool-change frequency.

A common failure mode is pushing control values before constraints are stable. Lock constraints first, then build a stable operating window with small increments.

Output interpretation

Interpret results in order: primary safety checks first, then stability, then economics.

  1. Safety: no machine, tool, or fixture limit violations.
  2. Stability: load, thermal, and vibration behavior remains controlled.
  3. Economics: cycle and cost align with shift target.

Current focus outputs include Interference, Contact pressure, Assembly force. If numbers conflict with floor behavior, verify units and inputs before changing strategy.

Geometry reference

Interference fit section

Use this figure to confirm variable naming and sign direction before entering values. This removes a common failure mode where the math is correct but variables are mapped to the wrong feature.

Typical failure modes and fixes

  • Sudden output jump: verify units, decimal precision, and input ordering first.
  • Unexpected trend: inspect workholding, tool condition, and thermal stability before retuning.
  • Big machine-to-machine delta: compare servo behavior, coolant coverage, spindle health, and compensation tables.
  • Shift handoff instability: enforce revision logging for program, tool, and parameter timestamp.

Keep rollback points and use single-variable increments to avoid coupled uncertainty.

FAQ

Can outputs be used directly for production?

Not immediately. Validate first piece, then short-run stability, then release to full production.

Why does floor behavior differ from computed values?

This is expected. Material lot, tool wear, thermal state, and machine dynamics all shift outcomes.

When should I recalculate?

Recalculate whenever tooling, fixturing, material lot, controller parameters, or takt target changes.

Final recommendation

Use Press Fit Calculator inside a fixed loop: baseline, first-piece validation, single-variable tuning, parameter freeze, and revision tracking. The outcome is not just one result but a repeatable process capability.