Comparison

F Numbers vs SUN

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

F Numbers

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
Read full description

F Numbers: Quick lookup of filler metal groupings for welding procedure and performance qualification. Lookup includes classifications with respective descriptions of intended use. Data is provided by C-spec. F-numbers and A-numbers assignments are based on ASME Section IX Table QW-432 and QW-442, ASME Section II Part C, AWS B2.1 Table B1 and B2, and AWS A5.1 through AWS A5.36.

About

SUN

Read full description

The SUN-TEC Hardness Converter is a tool for converting data from one hardness scale to another scale(s) and measuring the hardness of Metallic materials for your applications. Features and Benefits: - Convert between Rockwell, Vickers, Knoop, Brinell, and Leeb hardness scales. - Minimum Thickness and Cylindrical corrections for Rockwell scales. - Diagonal Length(s) conversion to Hardness and Hardness to Diagonal Length(s) for Vickers, Knoop, and Brinell scales. Available Scales: - HRA - HRB - HRC - HRD - HRF - HR15N - HR30N - HR45N - HR15T - HR30T - HR45T - VICKERS - KNOOP - BRINELL - LEEB (HLD) Note: All information within this application tool is for reference only.

Screenshots

F Numbers4 screens
SUN4 screens

Verdict

The call

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.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

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

UpkeepUpdate frequency

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.

Scorecard1 real difference · 8 level
F Numbers versus SUN: the parameters behind the verdict, then further details
ParameterF NumbersSUN
PriceFreeFree
Rating5.0 (3 ratings) — better—
Number of ratings3 — better—
Update frequencyEvery 13 months — betterEvery 14 months
AdsNo—
In-app purchasesNoNo
MonetizationFree—
DevicesiPhone, iPad, iPod — better—
Requires iOS13.0 — better13.4
Further details — not scored
Size15 MB24 MB
Age rating4+17+
DeveloperASMEIX CORPORATIONSUN-TEC CORPORATION

In-app purchases

None

F Numbers

No in-app purchases

None

SUN

No in-app purchases

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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