Unit Converter For Engineers vs Hardness Conversion Master
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Unit Converter For Engineers
This app provides a comprehensive unit conversion tool specifically designed for engineers, offering specialized units not found in standard converters. It features offline functionality, fast search, and a clean interface, replacing the need for multiple reference materials.
- Specialized engineering units
- Offline functionality
- Fast search and instant conversion
- Fraction input mode
- Ad-free interface
- Scientific notation support
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Built for engineers who work with units most converters don’t have. No ads. No popups. No distractions. If you’ve ever opened PDFs, charts, or old handbooks to convert Rockwell hardness, wire gauge, HVAC airflow, radiation dose, water hardness, or torque units — this app replaces all of that. Units you usually can’t find in converter apps Material Hardness Rockwell (HRC, HRB, HRA), Vickers, Brinell, Knoop, Mohs, Shore Wire Gauge AWG, SWG, MCM, kcmil, diameter, cross-sectional area HVAC & Airflow CFM, ACH, BTU/h, tons of cooling, kW, airflow per area and per person Water Quality & Chemistry ppm, mg/L as CaCO₃, grains per gallon (US/UK), °dH, °fH, dKH, mmol/L, meq/L Radiation & Radioactivity Becquerel, Curie, Gray, rad Mechanical & Structural Torque, stress, density, pressure, moment of inertia (kg·m² ↔ slug·ft²) Built for real work environments • Works 100% offline in labs, plants, and job sites • Fast search and instant conversion • Scientific notation for precision work • Fraction input mode for field and construction use • Clean, engineer-friendly interface — no ads, ever This app replaces reference charts, calculators, handbooks, and repeated Google searches with one reliable tool in your pocket. Pricing 7-Day Free Trial $9.99/year full access $29.99 lifetime access Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://unitconvertx.github.io/docs/privacy.html
Hardness Conversion Master
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A professional hardness conversion tool designed for mechanical engineering, metal heat treatment, and quality management, providing quick, stable, and traceable engineering reference data. **Key Features** 1. **Industrial-Grade Precision** The conversion logic is based on ASTM E140 / ASTM A370 standards, utilizing high-density reference points and linear interpolation to deliver stable and reproducible conversion results. 2. **Flexible Input and Real-Time Synchronization** Allows direct input in any hardness field (e.g., HRC / HV / HBW), with real-time conversion across other units, enhancing on-site operational efficiency. 3. **Physical Range Protection Mechanism** Built-in effective range checks for each scale, displaying "No Reference Value" when out of range, reducing the risk of misinterpretation. 4. **Customizable Interface** Enables toggling unit displays and drag-and-drop sorting to create a workspace tailored to individual or production line processes. 5. **Image Conversion (Beta)** Supports photo/album import, area selection recognition, result comparison, and manual correction, suitable for quick conversion of reports and on-site records. 6. **Batch Conversion** Allows multiple data entries for rapid conversion, retaining the last used unit preference to minimize repetitive actions. **Supported Units** - Rockwell: HRC, HRA, HRB, HRD, HRF - Superficial Rockwell: HR15N, HR30N, HR45N, HR15T, HR30T, HR45T - Brinell: HB, HBW - Vickers: HV - Tensile Strength: MPa
Screenshots
Verdict
The clearest difference is ads: Unit Converter For Engineers at none against Hardness Conversion Master's shown. Hardness Conversion Master's advantage is update cadence (every 3 days vs every 9 days). On price, in-app purchases, 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
Both are free to download. Unit Converter For Engineers sells 2 in-app purchases, starting at $9.99 per year and Hardness Conversion Master sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.
Unit Converter For Engineers ships an update every 9 days, Hardness Conversion Master every 3 days. The most recent releases landed on September 18, 2026 and August 31, 2026 respectively.
| Parameter | Unit Converter For Engineers | Hardness Conversion Master |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (3 ratings) — better | — |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 3 — better | — |
| Update frequency | Every 9 days | Every 3 days — better |
| Ads | No — better | Yes |
| In-app purchases | Yes | Yes |
| Monetization | Freemium | — |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 16.2 — better | 17.6 |
| Further details — not scored | ||
| Size | 5 MB | 259 MB |
| Age rating | 17+ | 4+ |
| Developer | Amanuel Abebaw | POYU WANG |
In-app purchases
Unit Converter For Engineers
- Annual Subscription7 Days trial$9.991 Year
- Lifetime Access$29.99
Hardness Conversion Master
- Unlock Pro$1.99





