1. What is Rockwell Hardness Scale Conversion?

Rockwell hardness scale conversion allows comparison of hardness values measured on different Rockwell scales (HRC, HRB, HRA, etc.). Since different scales use different indenters and loads, direct comparison requires conversion tables or formulas.

2. How Does the Calculator Work?

The calculator uses standard conversion tables from ASTM E140 or approximate formulas:

Note: Conversions are approximate and should be verified with official ASTM tables for critical applications.

3. Importance of Hardness Conversion

Details: Accurate hardness conversion is essential when comparing materials tested on different scales or when specifications reference a different scale than used in testing.

4. Using the Calculator

Tips: Enter the hardness value, select the original scale and target scale. The calculator will provide the approximate equivalent value.

5. Frequently Asked Questions (FAQ)

Q1: Why can't Rockwell scales be directly compared?
A: Different scales use different indenters (diamond cone vs. steel ball) and different loads, resulting in different measurement systems.

Q2: Are conversions exact?
A: No, conversions are approximate. For precise work, test using the required scale rather than converting.

Q3: Which scales can be converted?
A: Common conversions include HRC-HRB, HRB-HRA, HRC-HRA, but not all combinations have reliable conversions.

Q4: What's the most accurate conversion method?
A: The ASTM E140 standard provides the most authoritative conversion tables.

Q5: When should I not use conversions?
A: Avoid conversions when material specifications require testing on a specific scale or when high precision is needed.