The ongoing iPhone Duo fold test at a Louisville, Kentucky lab passed 75,000 folds as of 8:30 a.m. ET on Tuesday, October 27. Apple has not published a fold rating for the iPhone Duo, so there is no official figure to hold the result against.
CNET’s lab bought its iPhone Duo at an Apple Store on launch day, Friday, October 23, and loaded it into a machine it built called the Fold-a-Phone that afternoon. The machine opens and closes the foldable on a cycle of about four seconds, which works out to 900 folds an hour. At 50 folds a day, 75,000 folds is about four years of use.
Two earlier tests reached 32,640 and 10,000 folds
A four-night test on a custom folding machine reached 32,640 folds on a review unit with the iPhone Duo in a case. A push-pull gauge showed the hinge slightly stiffer afterward, and the tester could not feel a difference in daily use. A YouTuber folded an iPhone Duo 10,000 times at room temperature, then ran extra tests in sub-zero cold.
In that second test the crease deepened as the folds added up, and the hinge kept working smoothly. A separate lab test measured the crease at 48 microns on a new iPhone Duo and 167 microns after 3,000 folds. The lab’s 75,000 is more than double the 32,640-fold test.
The iPhone Duo fold test misses the cracking reports
The 75,000 folds come from a single iPhone Duo. Its 7.6-inch inner display folds between layers of high-strength glass over a titanium plate. Apple builds the hinge from more than 100 components.
Apple said on October 26 that a small number of units have an inner display issue. It has not said what causes it or how many are affected. One Australian owner reported a cracked inner screen six hours after unboxing and fewer than 20 openings.
A teardown of cracked units found the breaks cluster near the flex cable gap by the central hinge support. A fixed lab cycle adds no sand or dust to the hinge. In a separate durability test, dust entered around the hinge until the magnets could no longer pull the iPhone Duo shut.
The Fold-a-Phone runs a slow, pocket-style cycle
The lab built the cycle to match real use, where someone opens a foldable, spends a few minutes in an app, closes it and pockets it. The machine takes about one second each to open, fully open, close and fully close, which limits heat and hinge stress compared with a test built for speed. The cycle repeats until the hinge or a display gives out.
The machine tracks motor power draw to follow how the hinge opens and closes over time. The lab has started testing the Galaxy Z Fold 8 too, and it plans status updates and comparisons as testing continues.
