On Tuesday, we saw Apple introduce a new plastic iPhone. Why plastic? Because it's cheaper, sure. But it's also one of the smartest industrial design decisions Apple has ever made.
I can't put a dollar figure on what Apple's bill of materials for the 5C is, but it's safe to say that by going with plastic, they're saving a lot. And not just on material costs—also on time and labour. An aluminium iPhone has to undergo multiple stages of CNC machining and anodising. These are very time consuming processes that require an enormous number of man hours to oversee them. In contrast, an injection-moulded plastic shell can be produced in just one or two operations.
But the real key to the 5C design isn't just injection molding it out of plastic. It's injection molding it out of a single piece of plastic. This creates a stronger, simpler part—and it's going to produce much faster yield rates than Apple can currently get with the iPhone 5/5S.
This efficiency is the key to reducing costs on the iPhone 5C compared to aluminum iPhones. In the time it takes Apple to produce just one housing for the aluminium iPhone, they can make multiple plastic iPhones. The ability to produce iPhones quicker is a key feature for Apple as they try meet demand, especially in developing countries.
So yes—the iPhone 5C's plastic housing is cheaper because the material is less expensive. But the primary cost reduction is due to the fact that it takes fewer steps manufacture, which reduces the time and labor involved. I have no doubt that the 5C will become the best seller in Apple’s iPhone lineup overnight, if for no other reason than that they can produce so many more of them.
Is Apple's design team giving up much, in terms of the 5C's aesthetics? Plastic is cheap, but it also feels cheap, right? Well, that depends on the quality of the plastic, but more crucially, the injection moulding process. In this area, Apple is world class. Just look at the quality of the plastic housing on Apple TV, AirPort routers, or the EarPods.
The iPhone 5C’s hard plastic back gives us a glimpse into Apple's design process. Most plastic cases are made using a mould that includes holes for the speakers, buttons, and the camera. But with the 5C casing, Apple is choosing to use a CNC machine to create these holes after the shell has already been made. Why? First of all, this yields a stronger part. If those holes were included in the injection moulding process, hot plastic would have to flow around them. This creates weak points in the plastic. By machining those holes out, the plastic around the holes is just as strong as the rest of the shell. These cases will be stronger than the norm.
Second, the CNC solution allows Apple to focus on making the housing as seamless as possible. In most plastic products, you can see a faint line—called a "witness line"—that reveals where the two parts of the mould came together. By not moulding the holes, Apple only has to make sure they eliminate one witness line—along the glass display edge of the housing. In fact, you can see the CNC polishing wheel process they use for eliminating that witness line here:
Third, CNC machining these holes gives them a much tighter tolerance than if they were simply moulded into the part. Visually, this makes them look crisper and makes the fit between components like the SIM card tray and buttons feel very precise.
Apple also added an additional step of spray coating the backplate with a clear lacquer hard coat. This gives the plastic some of the qualities glazing gives pottery: It helps prevent scratching, makes the shell look extremely glossy, and completely changes how it feels in our hands. Instead of feeling like glossy plastic, the 5C should feel like ceramic.
Even the most minute elements of the 5C were designed to reduce the amount of detail found on the body of the 5S. The volume and lock buttons are the same colour as the plastic back, which means they blend into the housing. The headphone jack, lightning connector, and screws have all been tinted black to match the black display glass, too. I’ll say it again: Less. Visual. Clutter.
What will be missing from the 5C, though, is the feeling the 5/5S has when you pick it up. Even a year later, the aluminium iPhone feels impossibly thin and light. But comparing the plastic iPhone to the aluminium iPhone is a bit like comparing a gourmet hamburger to a gourmet steak. Both use the highest quality ingredients, but they’re designed for different audiences and occasions.
I prefer hamburger. In white, thank you. The iPhone 5C has fewer speaker holes, no dual-sided chamfers, no secondary glass pieces at the top and bottom, and no thin plastic dividers on the sides to make the external antenna work. It’s almost like Apple decided to use one of those simplified, outlined icons in its “Made for iPhone” program as the basis for this design.
It’s this simplicity that makes the 5C a much cleaner option compared to the aluminium 5S. By making the manufacturing process cheaper and more efficient, Apple has found a brilliant way to actually improve the design of the iPhone.