# F Numbers vs SUN

The clearest difference is device support: F Numbers at 3 against SUN's —. On price, update cadence, in-app purchases and iOS requirement there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

F Numbers ships an update every 13 months, SUN every 14 months. The most recent releases landed on September 15, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | F Numbers | SUN |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (3 ratings)](https://appshunter.io/ios/app/f-numbers/id929309069/reviews)** | — |
| Number of ratings | **3** | — |
| In-app purchases | No | No |
| Ads | No | — |
| Update frequency | **Every 13 months** | Every 14 months |
| Monetization | Free | — |
| Size | 15 MB | 24 MB |
| Requires iOS | **13.0** | 13.4 |
| Devices | **iPhone, iPad, iPod** | — |
| Age rating | 4+ | 17+ |
| Developer | [ASMEIX CORPORATION](https://appshunter.io/developer/911716652) | [SUN-TEC CORPORATION](https://appshunter.io/developer/1711446511) |

## What reviewers say

### F Numbers

[App page](https://appshunter.io/ios/app/f-numbers/id929309069)

Quickly find filler metal groupings for welding procedures and performance qualifications. Access classifications with descriptions of intended use, based on ASME and AWS standards.

**Highlights:** Filler metal grouping lookup, Welding procedure qualification, Performance qualification data, Classification descriptions, ASME Section IX data, AWS standards data

**Features:** macOS Compatibility

**In-app purchases:** none


### SUN

[App page](https://appshunter.io/ios/app/sun-tec/id6469055994)

**In-app purchases:** none


## Frequently asked questions

### Is F Numbers free?

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

### Is SUN free?

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

### Which is updated more often, F Numbers or SUN?

F Numbers ships an update every 13 months, and SUN every 14 months. Most recently, F Numbers was updated on September 15, 2026 and SUN on October 11, 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.*