---
title: "CT scan shows how the iPhone Duo hinge holds any angle from 15 to 145 degrees"
description: "HTX Studio's CT scan shows gears, springs and cams that let the iPhone Duo hold any angle from 15 to 145 degrees."
url: https://mactoreality.com/ct-scan-reveals-iphone-duo-hinges-six-section-design-and-15-145-degree-range
published: 2026-10-22T17:15:20Z
updated: 2026-10-22T17:15:20Z
author: "Mac to Reality Newsdesk"
category: News
tags: ["Accessories","iPhone"]
publisher: Mac to Reality
ai_assisted: true
apple_heat_impact: 3
---

# CT scan shows how the iPhone Duo hinge holds any angle from 15 to 145 degrees

*HTX Studio's CT scan shows gears, springs and cams that let the iPhone Duo hold any angle from 15 to 145 degrees.*

**Key points**

- HTX Studio's CT scan and 3D model split the iPhone Duo hinge into six sections, with gears keeping both halves in sync.
- Springs and cams let the screen hold any angle between 15 and 145 degrees; magnets close the last part.
- The fold leaves a teardrop-shaped gap of about 3.85mm; an 8H pencil left scratches you could feel.

YouTube channel HTX Studio has used a CT scan to look inside the iPhone Duo’s hinge, a day before Apple’s first foldable goes on sale on 23 October. Its analysis splits the hinge into six sections and found that the phone can hold its screen open at any angle between 15 and 145 degrees.

Because the team could not take its review unit apart, it combined the CT images with Apple’s official materials to build a 3D model of the mechanism. Pivot points link each half of the phone to a central shaft, and rows of gears pass rotation from one side to the other, so both halves always turn by the same amount. The mechanisms are mirrored at the top and bottom, and a gap in the middle leaves room for the flex cables that connect the two halves.

## How it holds an angle

The free-stop behaviour comes from springs pressing against shaped cams. “As we fold it, the cams compress the springs, which push back, and the resulting frictional torque overcomes the phone’s own weight,” HTX Studio explains in the video. Near the closed position, magnets take over and pull the two halves together.

Inside the fold, the hinge leaves space for the display to bend into a teardrop-shaped curve, which HTX measured at about 3.85mm at its widest point. The video also looks at the inner screen’s nano-texture surface, which scatters reflections and makes the crease harder to see.

## Scratch test

In a pencil-hardness test with a constant 100g load, a 6H pencil left faint marks that were visible under bright light but could not be felt, while an 8H pencil left scratches you could feel. Those are pencil grades, not Mohs hardness ratings. AppleInsider has a longer breakdown of the hinge findings.

The hinge was one of the most praised parts of the device in the first iPhone Duo reviews.

## Sources

- [HTX Studio: iPhone Duo Review: Folding Has a Price](https://www.youtube.com/watch?v=o1qc29t04GI)
- [AppleInsider: Inside the iPhone Duo's groundbreaking hinge's innovations](https://appleinsider.com/articles/26/10/22/inside-the-iphone-duos-groundbreaking-hinges-innovations)

*This report was written by the Mac to Reality newsdesk with AI assistance from the sources listed above, under the editorial policy at https://mactoreality.com/editorial-policy.*