Comparison

O vs Hydraulic Training Calculators

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

Head to head
About

O

Features
Read full description

Who hasn't sometimes wished for assistance when it comes to define the mounting dimensions for O-Rings or even find the right O-Ring? The Hutchinson O-Ring app offers precious tools: • Assembly aid, depending on the installation type (in a bore, on a piston, cover fitting with internal or external pressure) • Compounds compatibility with various fluids • Intelligent O-Ring measuring tool with the smartphone's camera function • Dimensions list for standard parts You can choose a reference number from thousands of available O-Rings and then precisely define the groove dimensions to ensure perfect sealing. On the contrary, after choosing the installation type and the groove dimensions, the app will recommend a list of compatible O-Ring dimensions. A smart measuring tool has been developed to measure your O-Rings dimensions. This can for instance be used in MRO for easy replacement. Take a coin to set the standard and watch your smartphone turn into a digital measure tool for precision seals! If chemistry classes are bad memories for you, the compound compatibility tool will help you to define the appropriate compound family, depending on the fluid used in your application. Bonus : get the PDF calculation results per email ! In order to confirm your choice, we recommend to validate with tests

About

Hydraulic Training Calculators

This app offers a comprehensive suite of hydraulic and fluid power tools, including calculators for power, thermal balance, and pipework. It provides design guides, a symbol library, and unit converters. Users can access free interactive content and a trial of paid resources, with options for one-time unlocks or annual subscriptions for extensive training materials.

Highlights
  • Hydraulic calculators
  • Symbol library
  • Unit converter
  • Design guides
  • Troubleshooting fault finder
  • Training courses
  • Simulation experiments
Features
Read full description

This hydraulic, fluid power app provides a wide range of industry-specific calculators, training, repair and design guides. Free interactive content (dark blue number) includes: Hydraulic calculators for power, pipework, thermal balance, and accumulators. Hydraulic symbol library. Engineering unit converter. Cylinder-valve and power unit design guides. Plus a free trial of all paid for design resources (mid blue number) and training course subscriptions (mid and light blue button) The hydraulic quiz and design guides unlock includes: Troubleshooting fault finder, Hydraulic hose register builder. Pipework sizing guide. Fitting assembly guide. Working safely tutorials and hydraulic quiz modules. Several simulation experiments. This is a one-time payment that can be restored on the user’s phone, at any time. Subscribe to access all training courses including: All of the above plus a range of hydraulic training resources including 75 text-based detailed explanations, 25 product simulations, 55 instructional videos, and 13 micro-learning tutorials. - The subscription is for one year and provides access to all training resources, quizzes, calculators and design guides. - Payment will be charged to the user iTunes Account at confirmation of purchase. - Subscription automatically renews unless auto-renew is turned off at least 24-hours before the end of the current period. - The user account will be charged for renewal within 24-hours prior to the end of the current period, and identify the cost of the renewal. - Subscriptions may be managed by the user and auto-renewal may be turned off by going to the user's Account Settings after purchase. - The free trial period will be forfeited when the user purchases an unlock or subscription. Full terms can be found at https://www.e4training.com/privacy3.php and user privacy statement at https://www.e4training.com/privacy1.php

Screenshots

O4 screens
Hydraulic Training Calculators4 screens

Verdict

The call

The clearest difference is in-app purchases: O at none against Hydraulic Training Calculators's 2. O also leads on update cadence (every 6 weeks vs every 4 months). On price, ads, device support 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. Hydraulic Training Calculators sells 2 in-app purchases, starting at $9.49 per year. O asks for nothing beyond the download.

UpkeepUpdate frequency

O ships an update every 6 weeks, Hydraulic Training Calculators every 4 months. The most recent releases landed on October 12, 2026 and October 15, 2026 respectively.

Scorecard2 real differences · 7 level
O versus Hydraulic Training Calculators: the parameters behind the verdict, then further details
ParameterOHydraulic Training Calculators
PriceFreeFree
Rating—5.0 (1 ratings) — better
Number of ratings—1 — better
Update frequencyEvery 6 weeks — betterEvery 4 months
AdsNoNo
In-app purchasesNo — betterYes
Monetization—Free with in-app purchases
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS12.0 — better13.2
Further details — not scored
Size40 MB16 MB
Age rating4+4+
DeveloperHUTCHINSONGary Molton

In-app purchases

None

O

No in-app purchases

2 purchases

Hydraulic Training Calculators

Subscriptions1
  • Annual Training Subscription$9.491 Year
One-time1
  • Hydraulic Quiz Design Guides$4.99

Questions

Is O free?
O is free to download, with no in-app purchases.
Is Hydraulic Training Calculators free?
Hydraulic Training Calculators is free to download, with in-app purchases available.
Do O or Hydraulic Training Calculators have ads?
Neither O nor Hydraulic Training Calculators shows ads.
Which is updated more often, O or Hydraulic Training Calculators?
O ships an update every 6 weeks, and Hydraulic Training Calculators every 4 months. Most recently, O was updated on October 12, 2026 and Hydraulic Training Calculators on October 15, 2026.

Other comparisons