Comparison

F Numbers vs Thread Calculator

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

Thread Calculator

This app provides a quick and easy way to calculate thread dimensions for various units, including tap hole sizes and bolt specifications. It helps metalworkers find precise measurements for internal and external threads without consulting tables.

Highlights
  • Thread cutting calculator for multiple units
  • Cold forming calculator
  • Thread repair calculator
  • Tap hole and bolt diameter calculation
  • Saves time compared to tables
Features
Read full description

The app includes: - A calculator for thread cutting for the following units: M, MF, UNC, UNEF, UNF, UNR, UNS, NPT, NPTF, NPSC, NPSF, NPSL, NPSM, BA, BSP, BSF, BSW, BSPP, TR, and TRF - A calculator for cold forming - A calculator for thread repair You want to know which tap hole you should drill for threading or which bolt you should use? With this app, you will find the desired measures in no time: Simply select the desired thread type, nominal size, and pitch and you will get the matching diameter for your project. This saves precious time you would have spent tediously searching for internal and external thread dimensions in tables. As this app is still in its development phase, new features will follow soon, so stay tuned! GSR Gustav Stursberg GmbH is a manufacturer for high-quality thread cutting tools with 130 years of operational experience in the area of threading tool production. The product portfolio includes a wide selection of tools for different areas of application. GSR taps, twist drills, round dies, and tool holders are manufactured to the highest quality standards in our own production facilities. The constant quality control during the production process guarantees a consistent good quality in all national as well as international production facilities. This requires enormous precision, which is reflected by our tools. Precision is in the details. Since 1889.

Screenshots

F Numbers4 screens
Thread Calculator4 screens

Verdict

The call

The clearest difference is rating: F Numbers at 5.0 against Thread Calculator's 4.3. F Numbers also leads on ads (none vs shown) and monetization model (free vs ad-supported). Thread Calculator's advantage is ratings volume (13 vs 3). On price, update cadence, in-app purchases and device support 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.

ReceptionRating · Positive reviews · Number of ratings

F Numbers holds the better App Store score, 5.0 against 4.3. Both are backed by a comparable volume of ratings — 3 and 13 respectively.

UpkeepUpdate frequency

F Numbers ships an update every 13 months, Thread Calculator every 18 months. The most recent releases landed on September 15, 2026 and September 9, 2026 respectively.

Scorecard5 real differences · 5 level
F Numbers versus Thread Calculator: the parameters behind the verdict, then further details
ParameterF NumbersThread Calculator
PriceFreeFree
Rating5.0 (3 ratings) — better4.3 (13 ratings)
Positive reviews—33.3% of reviews
Number of ratings313 — better
Update frequencyEvery 13 months — betterEvery 18 months
AdsNo — betterYes
In-app purchasesNoNo
MonetizationFree — betterAd-supported
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS13.0 — better15.0
Further details — not scored
Size15 MB25 MB
Age rating4+4+
DeveloperASMEIX CORPORATIONGSR Gustav Stursberg GmbH

Customer experience

F Numbers

All ratings3 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

Thread Calculator

All ratings13 ratings
Positive84.6%
Neutral7.7%
Negative7.7%
Written reviews3 reviews
Positive33.3%
Neutral0.0%
Negative66.7%

In-app purchases

None

F Numbers

No in-app purchases

None

Thread Calculator

No in-app purchases

Questions

Is F Numbers free?
F Numbers is free to download, with no in-app purchases.
Is Thread Calculator free?
Thread Calculator is free to download, with no in-app purchases.
Which has better reviews, F Numbers or Thread Calculator?
F Numbers is rated higher. F Numbers averages 5.0 out of 5 from 3 ratings, while Thread Calculator averages 4.3 from 13 ratings.
Do F Numbers or Thread Calculator have ads?
Thread Calculator shows ads; F Numbers does not.
Which is updated more often, F Numbers or Thread Calculator?
F Numbers ships an update every 13 months, and Thread Calculator every 18 months. Most recently, F Numbers was updated on September 15, 2026 and Thread Calculator on September 9, 2026.

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