# P Numbers vs SUN

The clearest difference is update cadence: SUN at every 14 months against P Numbers's every 39 months. P Numbers's advantage is device support. On price, 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.

P Numbers ships an update every 39 months, SUN every 14 months. The most recent releases landed on October 2, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | P Numbers | SUN |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (5 ratings)](https://appshunter.io/ios/app/p-numbers/id911716649/reviews)** | — |
| Number of ratings | **5** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | — |
| Update frequency | Every 39 months | **Every 14 months** |
| Monetization | Free | — |
| Size | 13 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

### P Numbers

[App page](https://appshunter.io/ios/app/p-numbers/id911716649)

Quickly access weldability grouping numbers for welding procedures and performance qualifications. This app provides data from authoritative sources like ASME Section IX and AWS B2.1.

**Highlights:** Base metal weldability grouping lookup, Welding procedure qualification data, Performance qualification data, ASME Section IX Table QW/QB-422 data, AWS B2.1 Table C1 and C2 data, ISO/TR 20173 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 P Numbers free?

P 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, P Numbers or SUN?

P Numbers ships an update every 39 months, and SUN every 14 months. Most recently, P Numbers was updated on October 2, 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.*