# O-Ring > O-Ring dimension calculator and material compatibility checker. (iPhone/iPad app by Trelleborg Sealing Solutions.) - Source: https://appshunter.io/ios/app/o-ring/id485346224 (this page in markdown: same URL + `.md`) - Developer: [Trelleborg Sealing Solutions](https://appshunter.io/developer/396863758) - Category: Productivity, Utilities - Price: Free - Rating: 3.80/5 from 5 App Store ratings · 12 written reviews indexed - Age rating: 12+ - Requires: iOS 12.1 · 26 MB - Languages: American English, German (Germany), Japanese, Chinese (Simplified, China) - Released: 2011-12-08 - Data updated: 2026-06-04 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/o-ring/id485346224/reviews.md ## What is O? 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 ## Key features - 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 ## Recent user reviews (10 of 12) All indexed reviews: https://appshunter.io/ios/app/o-ring/id485346224/reviews.md ### 1/5 — Useless *2024-08-03, version 4.4* Unfortunately useless Don’t bother with it ### 2/5 — App not working *2014-11-22, version 2.5* I've just found out the latest app does not open on my iPod touch running IOS 5.1.1 (earlier ones worked ok) It works fine on my iPad which is running the latest operating system. I can't see any comments that state it wouldn't work on the iPod but even after removing it and downloading it again it's still not opening. Normally apps won't download if the wrong version operating system is running. Does anyone have any ideas? Thanks, John. ### 5/5 — Great app! *2012-10-22, version 1.3* Really useful app for specifying o-rings. Almost as good as Trelleborg's superb web based o-ring calculator. ### 5/5 — Great Tool For Engineers *2012-01-23* As a mechanical engineer, I find this app very useful. I use it at least once a week. The layout of the app is very easy to work with and intuitive. A must have app for all engineers and for anyone who works with o-rings. Thanks Trelleborg for spending the time on this app. ### 5/5 — Quick reference. *2012-01-18* This is a great tool for quickly calculating o-ring sizes. I've mostly used the "quick search" to determine standard sizes. ### 5/5 — Another awesome app from Trelleborg *2012-01-17* Great time saver! ### 5/5 — O-ring tool *2012-01-17* This is a great tool for quick answers on the go. ### 5/5 — Sales *2012-01-17* Excellent tool & reference guide. Extensive fluid compatibility chart as well. Very helpful!! ### 5/5 — Everything I need at my fingertips *2012-01-17* Also good for unit conversion ### 5/5 — Sales *2012-01-17* Great application ## Frequently asked questions about O ### What is the O-Ring app used for? The O-Ring app is used to calculate O-Ring dimensions based on installation specifications and recommends O-Ring sizes according to ISO 3601 standards. It also checks chemical compatibility for various media. ### Does O-Ring have ads? No, the O-Ring app does not contain advertisements. It is a free application provided by Trelleborg Sealing Solutions. ### What standards does O-Ring support? O-Ring supports several national and international standards including ISO 3601-1 Class B (International), ISO 3601-1 Class A (AS 568, USA), NFT 47-502 (France), JIS B 2401 (Japan), and SMS 1586 (Sweden). ### Can I switch between metric and inch units in O-Ring? Yes, the O-Ring app allows you to easily switch between metric and inch measurements for your calculations. ### What is the rating for the O-Ring app? The O-Ring app has a rating of 3.8 stars from 5 ratings, indicating a generally positive user experience. ### What devices is O-Ring compatible with? O-Ring is compatible with iPhones, iPads, and iPods, as indicated by its supported devices list. ### How often is O-Ring updated? The O-Ring app was last updated on June 24, 2024, with version 4.4, suggesting regular maintenance and updates. ### What is the age rating for O-Ring? The O-Ring app has an age rating of 12+, making it suitable for users aged 12 and above. ## Version history (last 5 releases) ### 4.4 — 2024-06-24 Privacy Policy Update. ### 4.3 — 2023-10-04 - Added O-Ring alignment for tolerance and O-Ring search screen - Materials screen misalignment of materials and ratings are fixed. - Units are displayed in their respective languages. - Alignment issues in all screens are fixed. ### 4.2 — 2023-08-01 - Added O-Ring alignment for tolerance and O-Ring search screen - Materials screen misalignment of materials and ratings are fixed. - Units are displayed in their respective languages. ### 4.1 — 2021-08-04 - Added the ISO 3601-1 Class A (AS 568) O-Ring standard to the O-Ring Search and Tolerances pages - The O-Ring Search page was also updated with the France standard NFT 47-502 - Included Privacy Notice link for GDPR ### 4.0 — 2016-12-17 This app has been updated by Apple to display the Apple Watch app icon. New User Interface, Support for Japanese language and Bug fixes. ## Apps similar to O | App | Rating | Price | Category | | --- | --- | --- | --- | | [Walter Machining Calculator](https://appshunter.io/ios/app/walter-machining-calculator/id423564212) | 3.0 (5) | Free | Productivity | | [Thread Calculator](https://appshunter.io/ios/app/thread-calculator/id1559560290) | 4.3 (13) | Free | Productivity | | [Mechanical Engineer](https://appshunter.io/ios/app/mechanical-engineer/id327055140) | 4.4 (8) | Free | Productivity | | [CNC Machinist Calculator Pro](https://appshunter.io/ios/app/cnc-machinist-calculator-pro/id1037668281) | 4.7 (642) | $14.99 | Productivity | | [MechTab](https://appshunter.io/ios/app/mechtab/id553201101) | 4.1 (16) | Free | Productivity | | [Metal Calculator All In One](https://appshunter.io/ios/app/metal-calculator-all-in-one/id1589637862) | 4.3 (4) | Free | Productivity | ## More apps by Trelleborg Sealing Solutions - [ISO Fits](https://appshunter.io/ios/app/iso-fits/id396863755) - [Converter-Universal Conversion](https://appshunter.io/ios/app/converter-universal-conversion/id423521445) - [Aerospace Groove Selector](https://appshunter.io/ios/app/aerospace-groove-selector/id524363133) - [Glossary](https://appshunter.io/ios/app/glossary/id548601106) - [Shim Selector](https://appshunter.io/ios/app/shim-selector/id718147152) All apps by Trelleborg Sealing Solutions: https://appshunter.io/developer/396863758 ## Related topics [wellue o2 ring](https://appshunter.io/ios/topics/wellue-o2-ring) · [ring protein](https://appshunter.io/ios/topics/ring-protein) · [Bearing with spherical outer ring 9x24x7 mm](https://appshunter.io/ios/topics/bearing-with-spherical-outer-ring-9x24x7-mm) · [oluxury solutions](https://appshunter.io/ios/topics/oluxury-solutions) --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-04.*