But can Samsung foldables take the heat?

Just one month ago, Samsung unveiled two of its most advanced phones yet, the Galaxy Z Flip 4 and Fold 4. Although they feature plenty of cutting-edge technology, foldables are still somewhat fragile devices. You might want to keep these two away from sharp edges and other pointy objects, given how fragile they are compared to your average slab-of-glass phones. Still, Samsung's been making a point to highlight improvements it's made to durability over previous generations. Curious how true that might be, YouTuber Zack Nelson of JerryRigEverything has put the Galaxy Z Flip 4 through just the sort of trial by fire we'd expect from him.

Samsung's been doing its best to educate new foldable owners about just what they can expect from their phone's durability, complete with plenty of warnings in software — it clearly does not want a repeat of the original Galaxy Fold and incidents with people peeling off the screen protector. But for his tests, Nelson is consciously disregarding all these warnings — for the sake of consumer interest, of course.

In a hardness test, Samsung's Ultra-Thin Glass protecting the inner foldable display scratches at level two of the Mohs scale, with deeper grooves at level three — comparable to a sheet of plastic. That's going to have us thinking twice about even sharp fingernails around the screen when flipping the phone open with one hand.

To little surprise, the flexible layer protecting the foldable display doesn’t take to heat very kindly, physically deforming in seconds under a lighter’s flame. The 1.9-inch cover screen, on the other hand, merely discolors when subject to heat, and Gorilla Glass Victus protection ensures it doesn’t scratch easily, either.

Samsung does seem to have done a great job isolating the Galaxy Z Flip 4’s hinge from the elements. Unlike its predecessors, fold-cycling the hinge with fine sand and dirt on the screen doesn’t lead to scratchiness or affect its functionality. Bend-testing the phone by forcing the hinge backward breaks something inside with an audible "pop" that just sounds all sorts of expensive. On the outside, the phone remains fully functional, at least, thanks to the metallic back panels locking up, preventing the phone from snapping like a cookie.

Three magnets along the upper and lower edges of the Z Flip 4 are designed to hold the phone shut when folded. However, facing the fallout of Zack’s bend test, they proved no longer up to that task. On the bright side, though, the frame, volume rocker, and power button are all made of metal, so as long as you’re reasonably careful with the Z Flip 4, respecting the hinge’s limits and keeping the display far from hot and sharp things, you shouldn’t have any major issues. Like the Z Fold 4, Samsung’s Z Flip 4 ultimately passes Zack’s durability test with flying colors.

Chandraveer is a mechanical design engineer with a keen interest in all things Android, including devices, launchers, theming, apps, and photography. When he isn't using his mechanical keyboard, he's probably tweaking it or reading a book someone recommended. For him, unwinding usually entails four wheels, an engine, and great music.