When Apple CEO Tim Cook reveled the iPhone 6 Plus, he probably didn't think that its most talked about feature is its ability to bend.
Since the new iPhone 6 and 6 Plus began selling Friday, customers have complained that the phone bends and warps while in their pockets. The new generation of iPhones is much larger than previous generations – iPhone 6 is 4.7 diagonal inches and the iPhone 6 Plus is 5.5 inches – and many are wondering if the new size has anything to do with the bending problem.
"Previous iPhones were thicker and not as long. In material bending, larger cross sectional areas (thickness x width) and shorter lengths make things stronger (You can't easily bend a cube), while the opposite makes things very easy to bend (paper is easily folded)," Jeremy Irons, a design engineer at Creative Engineering, tells Gizmodo. "The increased length and decreased thickness contribute to the weakness of the new iPhone. Strength is proportionally related to length, but strength is affected much more by changes in thickness."
The new iPhones are also 0.02 inches thinner than pervious iPhones. And, according to Mr. Irons, that makes a big difference. "While the iPhone 5S was only 7% thicker than the iPhone 6 Plus, it was actually 22% stronger in bending. When you make something longer, it gets proportionally more bendable, when you make it thinner, it gets a lot more bendable," he says.
Adding to the bending problem is the aluminum case surrounding the phone. Aluminum is a light-weight and flexible metal. Apple uses anodized aluminum in its new phones, which is supposed to make them stronger, but that doesn't seem to be working.
"From an engineering standpoint, the iPhone is an amazingly small and delicately constructed device," Irons says. "The only thing really contributing to the structural integrity of the iPhone 6 Plus is the thin aluminum frame that covers the back and reaches around the sides. There is also another very thin piece of steel behind the glass, but we are not working with much as far as bending strength."
The number of people who have experienced the bending in the iPhone 6 and 6 Plus isn't clear, but it was enough for #BendGate to became a big topic on Twitter.
YouTube channel Unbox Therapy, which posted a video of the bending iPhone 6 Plus, tried to bend the Samsung Galaxy Note 3. After several attempts to bend the phone, the Samsung Galaxy Note 3 showed only slight signs of warping, but no damage was done.
News of bending phones came days after Apple announced that its iPhone 6 and 6 Plus sales were a record 10 million in the first weekend. That number doesn't include sales in China, one of the world's largest smart phone markets, because the phone is still waiting to be approved by regulators.
Apple has yet to comment on what, if anything, it will do about the bending of the new iPhones.