# ISO Fits vs Metal World

The clearest difference is rating: Metal World at 4.8 against ISO Fits's 4.2. Metal World also leads on in-app purchases (none vs 1) and update cadence (every 2 months vs every 5 months). On price, review sentiment, ratings volume and ads there is nothing between them.

Both are free to download. ISO Fits sells 1 one-off in-app purchase. Metal World asks for nothing beyond the download.

Metal World holds the better App Store score, 4.8 against 4.2. Both are backed by a comparable volume of ratings — 6 and 5 respectively. Written reviews point the same way: 95% of ISO Fits's written reviews are positive against 100% of Metal World's.

ISO Fits ships an update every 5 months, Metal World every 2 months. The most recent releases landed on November 6, 2026 and November 1, 2026 respectively.

## The numbers

| Metric | ISO Fits | Metal World |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.2 (6 ratings)](https://appshunter.io/ios/app/iso-fits/id396863755/reviews) | **[4.8 (5 ratings)](https://appshunter.io/ios/app/metal-world/id480664274/reviews)** |
| Number of ratings | **6** | 5 |
| Positive reviews | 94.6% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 2 months** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 66 MB | 37 MB |
| Requires iOS | 15.6 | **5.1.1** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Trelleborg Sealing Solutions](https://appshunter.io/developer/396863758) | [BIKAR-METALLE GmbH](https://appshunter.io/developer/480664277) |

## What reviewers say

### ISO Fits

[App page](https://appshunter.io/ios/app/iso-fits/id396863755)

Calculate ISO fits and tolerances for shafts and bores. Supports metric and inch units, displays detailed fit definitions, and includes visual charts and educational videos.

**Highlights:** ISO fits calculation, Tolerance class display, Metric/inch unit switching, Tolerance charts, Updated YouTube videos

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Full Version with complete ISO286 Standard | $1.99 | one-time |


### Metal World

[App page](https://appshunter.io/ios/app/metal-world/id480664274)

Quickly calculate the weight of various metal and plastic materials in numerous formats. Supports nearly 300 materials and 22 shapes, providing results per unit or total weight. Also offers material comparison and specific weight displays.

**Highlights:** Weight calculation for ~300 materials, Supports 22 formats (sheets, bars, tubes, etc.), Results per kg/m, m², or item, Specific weight display, Material comparison with EN/DIN standards, Information on special materials

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is ISO Fits free?

ISO Fits is free to download, with in-app purchases available.

### Is Metal World free?

Metal World is free to download, with no in-app purchases.

### Which has better reviews, ISO Fits or Metal World?

Metal World is rated higher. ISO Fits averages 4.2 out of 5 from 6 ratings, while Metal World averages 4.8 from 5 ratings.

### Do ISO Fits or Metal World have ads?

Neither ISO Fits nor Metal World shows ads.

### Which is updated more often, ISO Fits or Metal World?

ISO Fits ships an update every 5 months, and Metal World every 2 months. Most recently, ISO Fits was updated on November 6, 2026 and Metal World on November 1, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*