# Stress Intensity Factors Pro vs Mechanical Engineering Toolkit

The clearest difference is price: Mechanical Engineering Toolkit at Free against Stress Intensity Factors Pro's $5.99. Mechanical Engineering Toolkit also leads on rating (4.8 vs 4.0) and update cadence (every 5 days vs every 9 months). Stress Intensity Factors Pro's advantage is in-app purchases (none vs 1) and ads (none vs shown). On review sentiment and device support there is nothing between them.

Mechanical Engineering Toolkit is free to download; Stress Intensity Factors Pro costs $5.99 up front. Mechanical Engineering Toolkit sells 1 one-off in-app purchase. Stress Intensity Factors Pro asks for nothing beyond the download.

Mechanical Engineering Toolkit holds the better App Store score, 4.8 against 4.0. That said, the two scores are not equally well evidenced: Mechanical Engineering Toolkit has 64 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 50% of Stress Intensity Factors Pro's written reviews are positive against 57% of Mechanical Engineering Toolkit's.

Stress Intensity Factors Pro ships an update every 9 months, Mechanical Engineering Toolkit every 5 days. The most recent releases landed on November 1, 2026 and November 7, 2026 respectively.

## The numbers

| Metric | Stress Intensity Factors Pro | Mechanical Engineering Toolkit |
| --- | --- | --- |
| Price | $5.99 | **Free** |
| Rating | [4.0 (1 ratings)](https://appshunter.io/ios/app/stress-intensity-factors-pro/id726473168/reviews) | **[4.8 (64 ratings)](https://appshunter.io/ios/app/mechanical-engineering-toolkit/id1601099443/reviews)** |
| Number of ratings | 1 | **64** |
| Positive reviews | 50.0% of reviews | **57.1% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 9 months | **Every 5 days** |
| Monetization | Paid | **Free with in-app purchases** |
| Size | 10 MB | 48 MB |
| Requires iOS | **12.0** | 15.0 |
| Devices | iPhone, iPad, iPod | **iPhone, iPad, iPod, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [J.R.Hobbs](https://appshunter.io/developer/395110523) | [APPS BAY LIMITED](https://appshunter.io/developer/1599035519) |

## What reviewers say

### Stress Intensity Factors Pro

[App page](https://appshunter.io/ios/app/stress-intensity-factors-pro/id726473168)

Easily calculate Stress Intensity Factors (SIFs) for various fracture mechanics geometries. Input loads and dimensions to get instant "K" results, with options to share calculations via PDF.

**Highlights:** SIF calculations for multiple geometries, Input loads and dimensions, Automatic unit conversion (Imperial/Metric), Share results via PDF (email/Air Print), Universal app for iPad and iPhone

**Features:** Vision Pro support

**In-app purchases:** none


### Mechanical Engineering Toolkit

[App page](https://appshunter.io/ios/app/mechanical-engineering-toolkit/id1601099443)

This professional engineering calculator provides instant results for students, researchers, and practicing engineers. It offers detailed calculation steps, formulas, diagrams, and unit conversions. Save inputs as projects and export results in various formats.

**Highlights:** Engineering equations and formulas, Step-by-step calculation breakdowns, SI and Imperial unit conversions, Save and export results (text, image, CSV, PDF), Offline functionality, Extensive library of engineering tools

**Features:** Vision Pro support, iPhone Duo support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove Ads | $2.99 | one-time |


## Frequently asked questions

### Is Stress Intensity Factors Pro free?

Stress Intensity Factors Pro costs $5.99, with no in-app purchases.

### Is Mechanical Engineering Toolkit free?

Mechanical Engineering Toolkit is free to download, with in-app purchases available.

### Which has better reviews, Stress Intensity Factors Pro or Mechanical Engineering Toolkit?

Mechanical Engineering Toolkit is rated higher. Stress Intensity Factors Pro averages 4.0 out of 5 from 1 ratings, while Mechanical Engineering Toolkit averages 4.8 from 64 ratings.

### Do Stress Intensity Factors Pro or Mechanical Engineering Toolkit have ads?

Mechanical Engineering Toolkit shows ads; Stress Intensity Factors Pro does not.

### Which is updated more often, Stress Intensity Factors Pro or Mechanical Engineering Toolkit?

Stress Intensity Factors Pro ships an update every 9 months, and Mechanical Engineering Toolkit every 5 days. Most recently, Stress Intensity Factors Pro was updated on November 1, 2026 and Mechanical Engineering Toolkit on November 7, 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.*