# Fit Tolerance ISO vs mechanical design engine

The clearest difference is ads: mechanical design engine at none against Fit Tolerance ISO's shown. mechanical design engine also leads on update cadence (every 2 months vs every 12 months) and iOS requirement (13.0 vs 15.0). On price, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Fit Tolerance ISO ships an update every 12 months, mechanical design engine every 2 months. The most recent releases landed on November 2, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | Fit Tolerance ISO | mechanical design engine |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (2 ratings)](https://appshunter.io/ios/app/fit-tolerance-iso/id1251895012/reviews)** | — |
| Number of ratings | **2** | — |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | Every 12 months | **Every 2 months** |
| Monetization | Ad-supported | — |
| Size | 51 MB | 63 MB |
| Requires iOS | 15.0 | **13.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Yasar Yucel Yesilbag](https://appshunter.io/developer/1251895011) | [gan dae choi](https://appshunter.io/developer/1574341439) |

## What reviewers say

### Fit Tolerance ISO

[App page](https://appshunter.io/ios/app/fit-tolerance-iso/id1251895012)

Calculates engineering tolerances for various mechanical components based on ISO and ANSI standards. It determines size limits, deviations, and fit types for holes and shafts, offering schematic representations of fits.

**Highlights:** Calculates engineering tolerances, Supports ISO and ANSI standards, Determines clearance, transition, and interference fits, Provides schematic fit representations, Includes preferred tolerances and fits, Works with metric units

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### mechanical design engine

[App page](https://appshunter.io/ios/app/mechanical-design-engine/id1574341437)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Fit Tolerance ISO free?

Fit Tolerance ISO is free to download, with no in-app purchases.

### Is mechanical design engine free?

mechanical design engine is free to download, with no in-app purchases.

### Do Fit Tolerance ISO or mechanical design engine have ads?

Fit Tolerance ISO shows ads; mechanical design engine does not.

### Which is updated more often, Fit Tolerance ISO or mechanical design engine?

Fit Tolerance ISO ships an update every 12 months, and mechanical design engine every 2 months. Most recently, Fit Tolerance ISO was updated on November 2, 2026 and mechanical design engine on November 3, 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.*