# iEngineer vs OSG Calculator

The clearest difference is rating: iEngineer at 4.5 against OSG Calculator's 4.0. iEngineer also leads on ratings volume (201 vs 2) and review sentiment (86% vs 71%). OSG Calculator's advantage is in-app purchases (none vs 1) and update cadence (every 3 weeks vs every 5 months). On price, ads and device support there is nothing between them.

Both are free to download. iEngineer sells 1 one-off in-app purchase. OSG Calculator asks for nothing beyond the download.

iEngineer holds the better App Store score, 4.5 against 4.0. That said, the two scores are not equally well evidenced: iEngineer has 201 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 86% of iEngineer's written reviews are positive against 71% of OSG Calculator's.

iEngineer ships an update every 5 months, OSG Calculator every 3 weeks. The most recent releases landed on November 1, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | iEngineer | OSG Calculator |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.5 (201 ratings)](https://appshunter.io/ios/app/iengineer/id369825047/reviews)** | [4.0 (2 ratings)](https://appshunter.io/ios/app/osg-calculator/id606137246/reviews) |
| Number of ratings | **201** | 2 |
| Positive reviews | **85.5% of reviews** | 71.4% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 3 weeks** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 12 MB | 7 MB |
| Requires iOS | 26.0 | **6.0** |
| Devices | iPhone, iPad | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Perfectly Simple Apps LLC](https://appshunter.io/developer/357604157) | [OSG USA, INC.](https://appshunter.io/developer/606137309) |

## What reviewers say

### iEngineer

[App page](https://appshunter.io/ios/app/iengineer/id369825047)

Access a vast database of screw and bolt information, including dimensions, material grades, and strength properties for both US and metric fasteners. Features a comprehensive drill chart, unit conversion, and customizable material displays.

**Highlights:** Extensive US screw database, Metric screw database (in-app purchase), Detailed dimensions and material grades, Strength, torque, and clamp force data, Head markings and 3D head models, Comprehensive drill chart, Unit conversion and data export

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Metric Screws | $1.99 | one-time |

**What reviewers like**

- 🚀 Easy to navigate
- 👍 Comprehensive information
- 🔧 Useful for everyday work
- ⚙️ Essential for engineers and machinists
- 💡 Saves time compared to physical references

**What reviewers complain about**

- 🐛 Occasional errors in torque and tensile strength data
- 💰 Metric information requires paid upgrade
- 🔍 Missing some thread types like NPT and BSPP

**Reported bugs**

- Metric portion not working for some users
- Camera access request for no apparent reason

**Requested features**

- Add tap drill chart
- Include clearance hole fits
- Improve UI for larger displays
- Add French language support


### OSG Calculator

[App page](https://appshunter.io/ios/app/osg-calculator/id606137246)

This app calculates cutting parameters for drills, taps, and endmills. It also determines proper tap drill sizes based on desired thread percentage and provides decimal equivalents for various drill sizes.

**Highlights:** Cutting parameter calculation, Tap drill size calculation, Thread percentage adjustment, Decimal equivalent calculator, Support for Inch and Metric threads, NPT and NPS thread calculations

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is iEngineer free?

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

### Is OSG Calculator free?

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

### Which has better reviews, iEngineer or OSG Calculator?

iEngineer is rated higher. iEngineer averages 4.5 out of 5 from 201 ratings, while OSG Calculator averages 4.0 from 2 ratings.

### Do iEngineer or OSG Calculator have ads?

Neither iEngineer nor OSG Calculator shows ads.

### Which is updated more often, iEngineer or OSG Calculator?

iEngineer ships an update every 5 months, and OSG Calculator every 3 weeks. Most recently, iEngineer was updated on November 1, 2026 and OSG Calculator on October 6, 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.*