The iPhone 18 Pro is built around an aluminum unibody with Ceramic Shield 2 on the front and Ceramic Shield on the back. The iPhone Duo uses a Grade 5 titanium frame and hinge cover with the same two glass types on its closed faces, plus a custom polymer cover over its folding inner display. Both carry an IP68 rating to 6 meters for 30 minutes, according to Apple’s tech specs.
That makes the Duo the phone that brings titanium back to the iPhone after the 17 Pro generation moved to aluminum, and it is the first iPhone with a folding screen to protect. Here is what Apple has published about each phone’s materials and durability, and what it has not. Our iPhone Duo official specs guide has the full sheet.
iPhone 18 Pro vs iPhone Duo materials
| Material or rating | iPhone 18 Pro / Pro Max | iPhone Duo |
|---|---|---|
| Frame | Aluminum unibody | Grade 5 titanium, mirror-polished finish |
| Hinge | None | Grade 5 titanium cover, 3D-printed from 100 percent recycled titanium; more than 100 components |
| Front glass | Ceramic Shield 2 | Ceramic Shield 2 on the outer display |
| Back glass | Ceramic Shield | Ceramic Shield |
| Inner display cover | None | Custom polymer over high-strength glass layers, scratch-resistant coating, nano-texture finish |
| Water and dust | IP68, 6 meters for 30 minutes | IP68, 6 meters for 30 minutes |
| Recycled enclosure | 85 percent recycled aluminum | 85 percent recycled titanium |
| Recycled content overall | 40 percent | 35 percent |
| Battery cobalt | 100 percent recycled | 100 percent recycled |
| Weight | 211 g (Pro), 249 g (Pro Max) | 254 g |
| Thickness | 8.75 mm | 5.2 mm open, 11.3 mm closed |
| Colors | Black, Silver, Glacier, Burgundy | Night Sky, Star White |
Figures are from Apple’s tech specs and press releases for both phones.
Don’t miss the best of The Mac Observer
Set us as a preferred source and our Apple reporting ranks higher in your Google Search results and Discover feed — one tap, no account changes.
Aluminum unibody vs Grade 5 titanium
The iPhone 18 Pro continues the aluminum unibody design Apple introduced with the 17 Pro, with an enclosure made from 85 percent recycled aluminum. Apple’s press release for the 18 Pro also credits the design with room for a next-generation vapor chamber attached directly to the A20 Pro, which it says delivers about three times the cooling performance of the prior design.
The Duo goes the other way. Apple specifies Grade 5 titanium with a mirror-polished finish for the frame and the hinge cover, and says the enclosure uses 85 percent recycled titanium. The hinge cover is 3D-printed from 100 percent recycled titanium, and Apple says the hinge itself has more than 100 components with custom adhesives for flex relief. Apple has not published a hinge cycle rating.
Ceramic Shield 2 on both, plus a polymer cover on the Duo
Both phones put Ceramic Shield 2 on the front and Ceramic Shield on the back. On the Duo, the front means the 5.4-inch outer display, and Apple’s press release says Ceramic Shield 2 offers three times better scratch resistance.
The Duo’s 7.6-inch inner display needs something that bends. Apple describes a custom polymer cover with 40 percent higher stiffness than the industry standard, layered over high-strength glass, with an Apple-designed scratch-resistant coating and a nano-texture finish that reduces glare and minimizes the visible crease. Apple has not published a crease measurement or a drop rating for either phone.
Durability: the same IP68, different weights
Apple rates both phones IP68, with a maximum depth of 6 meters for up to 30 minutes. That is unusual for a foldable, and Apple’s own tagline for the Duo is that it is foldable, posable and durable.
The titanium and hinge add weight. The Duo is 254 g against 211 g for the iPhone 18 Pro and 249 g for the Pro Max. It is also thicker closed, at 11.3 mm against 8.75 mm, and thinner open, at 5.2 mm. The iPhone 18 Pro vs Pro Max guide compares the two aluminum models.
Recycled content: 40 percent vs 35 percent
- iPhone 18 Pro: 40 percent recycled content overall, 85 percent recycled aluminum enclosure, 100 percent recycled cobalt in the battery, 100 percent fiber-based packaging.
- iPhone Duo: 35 percent recycled content by weight, 85 percent recycled titanium enclosure, 100 percent recycled titanium hinge cover, 100 percent recycled cobalt, 60 percent renewable electricity in manufacturing, 100 percent fiber-based packaging.
The iPhone 18 Pro ships September 18 from $1,199, with the Pro Max from $1,299. The iPhone Duo opens pre-orders October 16 and ships October 23 from $1,999. Apple sells a $79 iPhone Duo Case and a $129 Folio with a kickstand, and updated Clear, silicone and FineWoven cases for the 18 Pro; Apple has not published their weights. Our iPhone 18 Pro official guide has the rest of the Pro’s specs.
