Press fit calculation — fixed 23mm interface diameter

Contact pressure, friction force/torque and stresses for an interference fit (Lame equations), with the interface diameter fixed at 23mm as in the original locked demo page.

✓ validated against legacyoriginal: /calculators/c5_14.htm

Press fit calculation — fixed 23mm interface diameter — original diagram from /calculators/c5_14.htm

Inner bore of inner ring, dᵢmmOuter diameter of outer ring, dₒmmContact length, LmmDiametral interference, δmmFriction coefficient, µYoung’s modulus inner, EᵢGPaPoisson inner, νᵢYoung’s modulus outer, EₒGPaPoisson outer, νₒ

Contact pressure, p13.15 MPa

Friction force, F2.28 kN

Maximum torque, T26.22 Nm

Stresses

σt inner ring @ dᵢ-107.82 MPa

σt inner ring @ d-94.68 MPa

σt outer ring @ d15.52 MPa

σt outer ring @ dₒ2.37 MPa

σe inner ring @ dᵢ107.82 MPa

σe inner ring @ d88.84 MPa

σe outer ring @ d24.85 MPa

σe outer ring @ dₒ2.37 MPa

The legacy "please login" demo lock froze the interface diameter d to 23 mm (also the page's own default). Every other input (bore/outer diameters, length, interference, friction, moduli, Poisson ratios) was already free to vary under the lock and remains free here — the formula itself is identical to the unlocked e3_8 model (press-fit.ts). Interference δ is typically δ/d ≈ 0.001 and should be corrected for surface roughness; assumes stresses stay below the elastic limit.

Method & references

Lame’s equations for thick-walled cylinders (elastic regime).
Default values represent a bronze bush in a steel flange.
FIXED GEOMETRY: interface diameter d = 23 mm — the original login gate forces this value regardless of input; see notes.

The computation is a literal port of the original client-side JavaScript from /calculators/c5_14.htm. Results are verified equal to the original by an automated golden-master test. No formula has been re-derived or “improved”.

Press fit calculation — fixed 23mm interface diameter — Engineering ABC