Calculator Input
Use the fields below to convert Vickers hardness into Rockwell A, B, or C values.
Plotly Graph
The graph shows the reference conversion curves used for interpolation. When a result exists, the current HV input is highlighted across the available scales.
Example Data Table
| Vickers (HV) | Approx. HRA | Approx. HRB | Approx. HRC |
|---|---|---|---|
| 120 | N/A | 60.00 | N/A |
| 180 | N/A | 79.00 | N/A |
| 240 | 58.00 | 93.00 | 20.00 |
| 320 | 63.00 | N/A | 34.33 |
| 450 | 70.00 | N/A | 47.00 |
| 650 | 79.00 | N/A | 58.00 |
Recent Calculation History
No calculations stored yet. Submit the form to build a downloadable history.
Formula Used
Direct hardness conversion is usually handled with reference tables rather than a single universal equation. This page uses piecewise linear interpolation between nearby tabulated points.
Rockwell value ≈ R1 + ((HV - HV1) / (HV2 - HV1)) × (R2 - R1)
where:
- HV is the entered Vickers hardness.
- HV1 and HV2 are the surrounding table points.
- R1 and R2 are the matching Rockwell values.
This method gives smooth estimates between known reference values. It is practical for comparison, reporting drafts, classroom work, and quick shop-floor screening.
How to Use This Calculator
- Enter a sample name for identification.
- Type the measured Vickers hardness value in HV.
- Select the Rockwell scale you want to estimate.
- Choose the number of decimal places for display.
- Add optional notes for your report or export file.
- Press Calculate Conversion to show the result above the form.
- Review the all-scale equivalents, graph, and history table.
- Download the result as CSV or PDF when needed.
Frequently Asked Questions
1) Is hardness conversion exact?
No. Conversion is approximate because hardness scales use different indenters, loads, and response behavior. Material composition and heat treatment also affect the relationship between Vickers and Rockwell values.
2) Why does the calculator use interpolation?
Reference tables often provide discrete points only. Interpolation fills the gap between those points, giving a smoother estimate for values that fall between listed Vickers entries.
3) Which Rockwell scale should I choose?
Choose the scale commonly used for your material and hardness range. HRB is often used for softer metals, while HRC and HRA are more common for harder materials and tooling comparisons.
4) Can I use this for certified acceptance testing?
Use it for estimation and planning, not as a replacement for the governing test standard. Final acceptance should rely on direct testing and the applicable specification for the material.
5) Why do some scales show N/A?
N/A means the entered Vickers value sits outside the approximate reference range for that Rockwell scale. In that case, choose another scale or verify the result with direct measurement.
6) Does the graph represent measured data?
The graph displays the stored reference points and the interpolation curves built from them. It helps visualize how hardness estimates change across the supported Vickers ranges.
7) What is the benefit of the history table?
History lets you compare multiple samples in one session, export them together, and keep quick records for reports, classroom exercises, or production checks.
8) Why include CSV and PDF downloads?
CSV files are convenient for spreadsheets and batch review. PDF files are useful for printouts, sharing, and attaching conversion summaries to testing or inspection documents.