Comparison

O 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

O

This app helps users calculate O-Ring dimensions and find compatible materials for their applications. It provides recommendations based on ISO standards and supports both metric and inch measurements.

Highlights
  • O-Ring housing calculation
  • O-Ring size recommendations by ISO standard
  • Quick search by national/international standards
  • O-Ring tolerance calculation
  • Metric and inch unit switching
  • Chemical compatibility check
  • Integration of Trelleborg Sealing Solutions Videos
Features
Read full description

The Trelleborg Sealing Solutions O-Ring App calculates O-Ring dimensions by simply entering installation specifications for your application in metric or inch. In addition, the App recommends O-Ring sizes according to ISO 3601 so you know exactly which part you need. Features at a Glance: - O-Ring Housing: After entering the bore or rod/shaft diameter, you will receive an O-Ring recommendation and O-Ring housing calculation according to the recommendations of ISO 3601 - O-Ring Quick Search: offers the selection of O-Ring nominal sizes according to the following national/international standards: ISO 3601-1 Class B (International), ISO 3601-1 Class A (AS 568, USA), NFT 47-502 (France), JIS B 2401 (Japan) SMS 1586 (Sweden) - Tolerances: calculation of O-Ring tolerances according to ISO 3601-1 Class B and Class A - Switch between metric and inch - Chemical compatibility check: find out which materials are compatible with the media used in your application. - Integration of Trelleborg Sealing Solutions Videos

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

O4 screens
Thread Calculator4 screens

Verdict

The call

The clearest difference is review sentiment: O at 83% against Thread Calculator's 33%. O also leads on ads (none vs shown) and update cadence (every 3 months vs every 18 months). Thread Calculator's advantage is rating (4.3 vs 3.8). On price, ratings volume, 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

Thread Calculator holds the better App Store score, 4.3 against 3.8. Both are backed by a comparable volume of ratings — 5 and 13 respectively. Written reviews complicate that: 83% of O's written reviews are positive against 33% of Thread Calculator's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

O ships an update every 3 months, Thread Calculator every 18 months. The most recent releases landed on June 4, 2026 and September 9, 2026 respectively.

Scorecard6 real differences · 4 level
O versus Thread Calculator: the parameters behind the verdict, then further details
ParameterOThread Calculator
PriceFreeFree
Rating3.8 (5 ratings)4.3 (13 ratings) — better
Positive reviews83.3% of reviews — better33.3% of reviews
Number of ratings513 — better
Update frequencyEvery 3 months — betterEvery 18 months
AdsNo — betterYes
In-app purchasesNoNo
MonetizationFree — betterAd-supported
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS12.1 — better15.0
Further details — not scored
Size26 MB25 MB
Age rating12+4+
DeveloperTrelleborg Sealing SolutionsGSR Gustav Stursberg GmbH

Customer experience

O

All ratings5 ratings
Positive60.0%
Neutral20.0%
Negative20.0%
Written reviews12 reviews
Positive83.3%
Neutral0.0%
Negative16.7%

Thread Calculator

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

In-app purchases

None

O

No in-app purchases

None

Thread Calculator

No in-app purchases

Questions

Is O free?
O 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, O or Thread Calculator?
Thread Calculator is rated higher. O averages 3.8 out of 5 from 5 ratings, while Thread Calculator averages 4.3 from 13 ratings.
Do O or Thread Calculator have ads?
Thread Calculator shows ads; O does not.
Which is updated more often, O or Thread Calculator?
O ships an update every 3 months, and Thread Calculator every 18 months. Most recently, O was updated on June 4, 2026 and Thread Calculator on September 9, 2026.

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