Press fit of a thin-walled tube
Contact pressure, mounting/friction force and transmission torque for a press fit of a thin-walled tube, from the tube’s hoop (tensile) stress at assembly.
Contact pressure, p = 2sσ/d104 MPa
Mounting force, F = µpπdL19.6 kN
Transmission torque, T = Fd/2196.04 Nm
Method & references
- Thin-walled tube interference fit, hoop-stress relation p = 2sσ/d.
- For σ < Rp0.2, σ follows Hooke’s law σ = E·ε with ε = δ/D; the standard elastic press-fit calculator (c5_14) can also be used in that regime.
- For σ > Rp0.2, the stress-strain curve flattens, so σ stays roughly constant between Rp0.2 and the ultimate tensile strength Rm even for a few percent strain.
The computation is a literal port of the original client-side JavaScript from /calculators/c5_15.htm. Results are verified equal to the original by an automated golden-master test. No formula has been re-derived or “improved”.