iPhone Duo shows white line after 75,000 hand folds in durability test

CNET is running a durability test on Apple's iPhone Duo using a custom Fold-a-Phone machine that opens and closes the device at roughly 20,000 cycles per day. The test has now passed 60,000 folds since launch day, with the phone still functioning and the test continuing.

YouTuber Kuba Klawiter was folding an iPhone Duo by hand when a bright white line appeared around 75,000 cycles. Another review unit showed no noticeable change after 32,000 folds, though test methods differed between the various durability tests.

YouTuber JerryRigEverything conducted extreme durability tests on the iPhone Duo, pouring sand and dust onto the device and its hinge. The debris caused the hinge to jam and prevented the phone from closing completely, despite its IP68 dust and water resistance rating.

In a reverse fold test, JerryRigEverything bent the iPhone Duo backwards against its normal folding direction. The inner screen developed a permanent green line extending from the fold area to the edge after the first attempt, and two additional lines appeared after a second attempt. The screen eventually lost touch functionality, though it still displayed an image.

The outer screen with second-generation Ceramic Shield showed scratches at Mohs hardness level 7, while the inner folding screen showed marks at level 2 and could be damaged by fingernail pressure. Apple has not provided an official fold rating for the device.