What 32,000 Folds Did to the iPhone Duo's Hinge

Apple has not disclosed the results of hinge tests for the iPhone Duo or provided a lifetime fold number, similar to Samsung. To assess the iPhone Duo's hinge durability, journalist Joanna Stern subjected her review unit to over 32,000 folds over four nights. During this extensive testing period, Stern noticed the hinge feeling slightly looser as the number of folds increased, but ultimately concluded she could not sense a significant difference in the hinge's stiffness.

A calibrated push-pull gauge confirmed that the hinge became even stiffer after the folding test. In daily use, Stern could not discern any discernible difference after the 32,000 folds, indicating the iPhone Duo's hinges remained remarkably consistent. Stern did not comment on whether the extensive folding affected the visible crease, an issue observed in other foldable devices over time.

Her testing was conducted with a case on, and while the machine could open the iPhone Duo flat, it did not close entirely each time. Samsung's foldable displays have undergone official durability tests, with the display used in the Galaxy Z Fold7 successfully passing a 500,000-fold test. According to Samsung Display, this translates to over 10 years of average daily usage (100 folds per day) or six years for heavier daily folders (200+ folds per day).

Until Apple shares information on the iPhone Duo's display and hinge durability, Stern's test serves as the sole available data point. Further unofficial folding stress tests are expected in the coming weeks. The full details on Stern's testing machine, including its construction, are available in her YouTube video and review writeup.