Hertz point contact

Contact radius, elastic approach, mean and maximum contact pressure, and contact stiffness for two bodies in point contact (Hertz theory).

✓ validated against legacyoriginal: /calculators/e2_1.htm

Young’s modulus body 1, E₁GPaPoisson body 1, ν₁Young’s modulus body 2, E₂GPaPoisson body 2, ν₂Radius body 1, R₁ (0 = flat)mmRadius body 2, R₂ (0 = flat)mmNormal force, FN

Contact radius, a0.15 mm

Elastic approach, δ4.37 µm

Mean pressure, pₘ1.46 GPa

Max pressure, p₀2.19 GPa

Contact stiffness, S34.36 N/µm

Reduced modulus, E*232.6 GPa

Reduced radius, R*2.5 mm

Method & references

Hertz contact theory for elastic bodies in point contact.
A radius of 0 represents a flat surface (ball on plane).

The computation is a literal port of the original client-side JavaScript from /calculators/e2_1.htm. Results are verified equal to the original by an automated golden-master test. No formula has been re-derived or “improved”.