Comparison

Hydraulic Engineer vs 3DX Catalogs

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

Head to head
About

Hydraulic Engineer

This comprehensive calculator app offers over 1,000 hydraulic engineering formulas across 13 categories. It includes temperature conversions, reference tables, and the ability to save and share calculations. Works offline and supports both US Customary and SI Metric units.

Highlights
  • Over 1,000 hydraulic formulas
  • 13 specialized calculator categories
  • Temperature scale converters
  • Professional reference tables
  • Save and share calculations
  • Works offline
  • US Customary and SI Metric units
Features
Read full description

HYDRAULIC ENGINEER is the most comprehensive hydraulic engineering calculator available on the App Store, featuring over 1,000 formulas across 13 specialized calculator categories, 8 temperature scale converters, and 8 professional reference tables. CALCULATOR CATEGORIES - Actuator Formulas — cylinder force, stroke, speed, and rod calculations - Fluid Power — pressure, flow, horsepower, and torque calculations - Pump Laws — affinity laws for speed, flow, pressure, and power - Vehicle Drive — drive speed, tractive effort, gradeability, and drawbar pull - Hydraulic Tubing — wall thickness, burst pressure, and working pressure - Cylinder Calculations — extend/retract speed, rod end area, and cycle times - Thermal Hydraulics — heat generation, reservoir cooling, heat exchangers, and energy to heat fluid - Oil Velocity & Pressure Loss — pipe velocity, pressure drop per foot, and total system losses - Pipe Flow — Reynolds number, Darcy-Weisbach head loss, laminar friction, and orifice flow - Accumulator Sizing — discharge volume, precharge pressure, adiabatic and isothermal gas volumes - Reservoir Sizing — open/closed circuit sizing, cylinder-based sizing, and oil weight calculations - AC/DC Electrical — Ohm's law, power, resistance, inductance, and motor selection - Area Formulas — 60 geometric area calculations for every common shape 700+ CONVERSION FORMULAS Pressure, horsepower, BTU, flow rates, linear measure, square measure, cubic measure, liquid measure, weights, watts, power, HVAC, metric, sand-to-volume, and fraction conversions. 8 TEMPERATURE SCALES Convert between Celsius, Fahrenheit, Kelvin, Rankine, Reaumur, Newton, Delisle, and Romer — 56 conversion formulas covering every combination. 8 PROFESSIONAL REFERENCE TABLES - Pipe Schedule (Schedule 40 & 80) - ISO Viscosity Grades - Recommended Flow Velocities - Hydraulic Hose Sizing (SAE) - JIC Thread Sizes - Pipe Roughness Values - O-Ring Sizes (AS568) - Wire Rope Working Load Limits KEY FEATURES - Save and share any calculation result - Share reference tables - Calculation history - Favorites for quick access to your most-used formulas - Switch between US Customary and SI Metric units - Dual-unit display shows both US and metric values simultaneously - Dark mode optimized interface - Works offline — no internet connection required PREMIUM UPGRADE Unlock sharing, advanced calculator sections, and unlimited history with a one-time lifetime purchase — no subscriptions. HYDRAULIC ENGINEER is designed for working hydraulic engineers, technicians, maintenance professionals, and engineering students. If there are formulas or reference tables you'd like to see added, just use the built-in feedback feature to let us know.

About

3DX Catalogs

Features
Read full description

Our supplier certified catalogs of configurable models, with parametric part numbers, lets you access millions of models with a few simple picks. All popular CAD formats supported. All FREE via your smartphone or tablet. It's as easy as 1 – 2 – 3. 1. Open a catalog, select a product, pick your options. 2. Evaluate the selected model from the auto-generated 3D preview. 3. Then you can: Email the model. Generate an instant RFQ.

Screenshots

Hydraulic Engineer4 screens
3DX Catalogs4 screens

Verdict

The call

The clearest difference is price: 3DX Catalogs at Free against Hydraulic Engineer's $4.99. 3DX Catalogs also leads on in-app purchases (none vs 1) and iOS requirement (10.0 vs 18.6). On ads 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

3DX Catalogs is free to download; Hydraulic Engineer costs $4.99 up front. Hydraulic Engineer sells 1 one-off in-app purchase. 3DX Catalogs asks for nothing beyond the download.

Scorecard3 real differences · 7 level
Hydraulic Engineer versus 3DX Catalogs: the parameters behind the verdict, then further details
ParameterHydraulic Engineer3DX Catalogs
Price$4.99Free — better
Rating4.0 (1 ratings) — better—
Positive reviews25.0% of reviews—
Number of ratings1 — better—
Update frequencyEvery 6 months—
AdsNoNo
In-app purchasesYesNo — better
MonetizationPaid—
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS18.610.0 — better
Further details — not scored
Size19 MB43 MB
Age rating4+4+
DeveloperHistorycentral.comEndeavor Business Media LLC

In-app purchases

1 purchases

Hydraulic Engineer

One-time1
  • Hydraulic Pro$3.99
None

3DX Catalogs

No in-app purchases

Questions

Is Hydraulic Engineer free?
Hydraulic Engineer costs $4.99, and also offers in-app purchases.
Is 3DX Catalogs free?
3DX Catalogs is free to download, with no in-app purchases.
Do Hydraulic Engineer or 3DX Catalogs have ads?
Neither Hydraulic Engineer nor 3DX Catalogs shows ads.

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