# Bolt Length vs ThreadFon Multi

The clearest difference is review sentiment: ThreadFon Multi at 80% against Bolt Length's 33%. ThreadFon Multi also leads on rating (3.8 vs 3.0) and in-app purchases (none vs 1). On price, ratings volume and device support there is nothing between them.

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

ThreadFon Multi holds the better App Store score, 3.8 against 3.0. Both are backed by a comparable volume of ratings — 2 and 4 respectively. Written reviews point the same way: 33% of Bolt Length's written reviews are positive against 80% of ThreadFon Multi's.

Bolt Length ships an update every 20 months, ThreadFon Multi monthly. The most recent releases landed on August 2, 2026 and September 9, 2026 respectively.

## The numbers

| Metric | Bolt Length | ThreadFon Multi |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.0 (2 ratings)](https://appshunter.io/ios/app/bolt-length-nominal-length/id1042345193/reviews) | **[3.8 (4 ratings)](https://appshunter.io/ios/app/threadfon-multi-thread-calc/id1602169811/reviews)** |
| Number of ratings | 2 | **4** |
| Positive reviews | 33.3% of reviews | **80.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 20 months | **Monthly** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 6 MB | 43 MB |
| Requires iOS | 14.0 | **12.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [mitsunori oishi](https://appshunter.io/developer/905649994) | [Dmitriy Trofimov](https://appshunter.io/developer/1598378710) |

## What reviewers say

### 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 |


### ThreadFon Multi

[App page](https://appshunter.io/ios/app/threadfon-multi-thread-calc/id1602169811)

This tool provides detailed insights into metric, inch, pipe, and trapezoidal cylindrical threads based on ISO and ASME standards. It helps users efficiently determine essential thread specifications for various thread types.

**Highlights:** ISO Metric thread support, Unified Inch thread support, Pipe thread support, Trapezoidal thread support, Based on ISO 965 and ASME B1.1 standards, Determines fundamental thread parameters

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

**In-app purchases:** none


## Frequently asked questions

### Is Bolt Length free?

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

### Is ThreadFon Multi free?

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

### Which has better reviews, Bolt Length or ThreadFon Multi?

ThreadFon Multi is rated higher. Bolt Length averages 3.0 out of 5 from 2 ratings, while ThreadFon Multi averages 3.8 from 4 ratings.

### Do Bolt Length or ThreadFon Multi have ads?

Bolt Length shows ads; ThreadFon Multi does not.

### Which is updated more often, Bolt Length or ThreadFon Multi?

Bolt Length ships an update every 20 months, and ThreadFon Multi monthly. Most recently, Bolt Length was updated on August 2, 2026 and ThreadFon Multi on September 9, 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.*