Ideambox
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TOOL IDB-MEC-002
Snap-fit stress

Desktop only

Engineering tools are available only on desktop screens.

Snap-fit stress

Peak bending strain on a rectangular cantilever snap during assembly. Compare against the resin's allowable strain — if you exceed it, the hook breaks on first install.

Cantilever beam — deflection ε = —
δ L = 15 mm h
Engineering notes

Formula (rectangular cantilever)

  • εmax = 1.5 · h · δ / L²
  • σ = E · ε

Sanity rules

  • One-time assembly: ε < 70% allowable.
  • Reusable snap: ε < 40% allowable.
  • Taper the beam for more uniform stress — tip strain drops 30–50%.
  • Round the inside corner where snap meets housing.

Result

Live