KEVOS® MAKEOS · Mechanics

Wedge Force with Friction

What force drives this wedge under a load, and will it stay in place?

Force to drive and to withdraw a wedge that raises a guided load, with friction on both wedge faces, and the self-locking check.

Open the calculatorRuns in your browser. No account needed.

How this tool works

Inputs, units and where to find them

InputUnitTypical source
Load on the wedgeNLoad the wedge supports or lifts, perpendicular to its base.
Wedge angle°Angle between the two wedge faces (taper angle).
Coefficient of friction (both faces)Friction coefficient for the wedge faces, assumed equal on both faces.

Method and formulas

  1. Friction angle φ = atan μ.
  2. Driving force P = W tan(α + 2φ).
  3. Withdrawal force P′ = W tan(2φ − α); if 2φ > α the wedge is self-locking.
  4. Example: a 6° wedge under 10000 N needs 4,257.4 N to drive and 1,955 N to withdraw.

Limitations

  • Simple wedge with the load guided perpendicular to the base; guide friction is not included.
  • Friction varies widely; vibration can release a nominally self-locking wedge.
  • Example values are illustrations. Replace them with values for your actual task.

Typical uses

  • Size wedge levelling mounts and jacks
  • Check that a wedge or taper key stays in place
  • Estimate force to remove a taper key

Who it is for

  • Design engineers
  • Maintenance engineers
  • Machine builders

What you get

  • Force to drive the wedge
  • Force to withdraw it
  • Self-locking or not

Interpreting the result

  • Use a small wedge angle for fine adjustment and self-locking; it needs more travel.

References

  • Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 169–171. 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 Wedge Force with Friction calculator