# Virtual Flange Slide Rule vs Drill Collar

The clearest difference is price: Virtual Flange Slide Rule at Free against Drill Collar's $0.99. Virtual Flange Slide Rule also leads on update cadence (every 4 months vs every 36 months) and device support (3 vs 1). On ads, in-app purchases and iOS requirement there is nothing between them.

Virtual Flange Slide Rule is free to download; Drill Collar costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Virtual Flange Slide Rule ships an update every 4 months, Drill Collar every 36 months. The most recent releases landed on October 2, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | Virtual Flange Slide Rule | Drill Collar |
| --- | --- | --- |
| Price | **Free** | $0.99 |
| Rating | **[5.0 (13 ratings)](https://appshunter.io/ios/app/virtual-flange-slide-rule/id546358145/reviews)** | — |
| Number of ratings | **13** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 4 months** | Every 36 months |
| Monetization | Free | — |
| Size | 3 MB | 1 MB |
| Requires iOS | **15.0** | 16.4 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [American Certified Equipment, Inc.](https://appshunter.io/developer/546358148) | [zhandos uakanov](https://appshunter.io/developer/625286817) |

## What reviewers say

### Virtual Flange Slide Rule

[App page](https://appshunter.io/ios/app/virtual-flange-slide-rule/id546358145)

Access essential measurements and dimensional data for API 6A integral flanges. This tool provides quick access to critical specifications for engineering and industrial applications.

**Highlights:** API 6A integral flange data, Relevant measurements, Dimensional data access, Engineering specifications

**Features:** macOS Compatibility

**In-app purchases:** none


### Drill Collar

[App page](https://appshunter.io/ios/app/drill-collar/id1292363783)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Virtual Flange Slide Rule free?

Virtual Flange Slide Rule is free to download, with no in-app purchases.

### Is Drill Collar free?

Drill Collar costs $0.99, with no in-app purchases.

### Do Virtual Flange Slide Rule or Drill Collar have ads?

Neither Virtual Flange Slide Rule nor Drill Collar shows ads.

### Which is updated more often, Virtual Flange Slide Rule or Drill Collar?

Virtual Flange Slide Rule ships an update every 4 months, and Drill Collar every 36 months. Most recently, Virtual Flange Slide Rule was updated on October 2, 2026 and Drill Collar on October 8, 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.*