# MechTab vs Bolt Length

The clearest difference is review sentiment: MechTab at 89% against Bolt Length's 33%. MechTab also leads on rating (4.1 vs 3.0) and in-app purchases (none vs 1). On price, device support and iOS requirement there is nothing between them.

Both are free to download. Bolt Length sells 1 one-off in-app purchase. MechTab asks for nothing beyond the download.

MechTab holds the better App Store score, 4.1 against 3.0. That said, the two scores are not equally well evidenced: MechTab has 16 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 89% of MechTab's written reviews are positive against 33% of Bolt Length's.

MechTab ships an update every 9 months, Bolt Length every 20 months. Both last shipped on November 1, 2026.

## The numbers

| Metric | MechTab | Bolt Length |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.1 (16 ratings)](https://appshunter.io/ios/app/mechtab/id553201101/reviews)** | [3.0 (2 ratings)](https://appshunter.io/ios/app/bolt-length-nominal-length/id1042345193/reviews) |
| Number of ratings | **16** | 2 |
| Positive reviews | **88.6% of reviews** | 33.3% of reviews |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | **Every 9 months** | Every 20 months |
| Monetization | **Free** | Free with in-app purchases |
| Size | 9 MB | 6 MB |
| Requires iOS | 15.0 | **14.0** |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Werder AG](https://appshunter.io/developer/553201104) | [mitsunori oishi](https://appshunter.io/developer/905649994) |

## What reviewers say

### MechTab

[App page](https://appshunter.io/ios/app/mechtab/id553201101)

This app offers a comprehensive set of tools for mechanics, providing essential data on tolerances, threads, cutting speeds, wrench sizes, and roughness. It also includes calculators for material weight, triangle properties, and trowalisation.

**Highlights:** ISO-Tolerance data (holes and shafts), Thread specifications, Cutting data calculations, Wrench size conversions, Roughness parameters, Material weight calculator, Triangle property calculator

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

**In-app purchases:** none


### Bolt Length

[App page](https://appshunter.io/ios/app/bolt-length-nominal-length/id1042345193)

This application helps calculate the length of metric coarse screws based on Japanese Industrial Standards. It is designed for mechanical design purposes and should be used at the user's own risk.

**Highlights:** Metric coarse screw length calculation, Conforms to Japanese Industrial Standards (JIS), Designed for mechanical design, User risk disclaimer

**Features:** macOS Compatibility, Family Sharing

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Hide Ads | $1.99 | one-time |


## Frequently asked questions

### Is MechTab free?

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

### Is Bolt Length free?

Bolt Length is free to download, with in-app purchases available.

### Which has better reviews, MechTab or Bolt Length?

MechTab is rated higher. MechTab averages 4.1 out of 5 from 16 ratings, while Bolt Length averages 3.0 from 2 ratings.

### Do MechTab or Bolt Length have ads?

Bolt Length shows ads; MechTab does not.

### Which is updated more often, MechTab or Bolt Length?

MechTab ships an update every 9 months, and Bolt Length every 20 months. Most recently, MechTab was updated on November 1, 2026 and Bolt Length 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.*