# Hardness Conversion Master — ASTM Hardness Converter Pro

> ASTM Hardness Converter Pro (iPhone/iPad app by POYU WANG.)

- Source: https://appshunter.io/ios/app/hardness-conversion-master/id6760411989 (this page in markdown: same URL + `.md`)
- Developer: [POYU WANG](https://appshunter.io/developer/1883764660)
- Category: Utilities
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 17.6 · 259 MB
- Languages: British English, French (France), German (Germany), Hindi, Italian, Japanese, Korean, Polish, Brazilian Portuguese, Chinese (Simplified, China) and 5 more
- Released: 2026-03-17
- Data updated: 2026-08-31
- User reviews in markdown: https://appshunter.io/ios/app/hardness-conversion-master/id6760411989/reviews.md

## What is Hardness Conversion Master?

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

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Unlock Pro | $1.99 | one-time |



## Version history (last 5 releases)

### 1.1.1 — 2026-08-27

Improved user experience and stability.

### 1.1.0 — 2026-05-27

- Added multilingual support
- Introduced batch conversion
- Introduced batch image conversion (beta version)
- Added built-in user guide
- Optimized interface
- Stability and performance enhancements

### 1.0.9 — 2026-04-07

Fixed language display issues.

### 1.0.8 — 2026-04-06

Performance optimizations and stability improvements.

### 1.0.7 — 2026-04-03

Performance optimizations and stability improvements.

## More apps by POYU WANG

- [Mahjong Chip Manager](https://appshunter.io/ios/app/mahjong-chip-manager/id6760308249)
- [Super Pure Calculator](https://appshunter.io/ios/app/super-pure-calculator/id6762529424)

All apps by POYU WANG: https://appshunter.io/developer/1883764660

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*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 2026-08-31.*