Provide the test load and both indentation diagonals. Choose units carefully for correct results.
The Vickers hardness number is computed from the applied load and the indentation’s average diagonal:
- d = (d1 + d2) / 2
- HV = 1.8544 × F(kgf) / d²(mm²)
If the load is entered in newtons, it is converted using 1 kgf = 9.80665 N.
- Enter the test load used during indentation.
- Select the load unit that matches your instrument.
- Measure both diagonals and enter d1 and d2.
- Choose the diagonal unit used in your microscope scale.
- Press Calculate to view hardness above the form.
- Use CSV or PDF export for lab notes and reports.
| Load | d1 | d2 | Average d | Hardness |
|---|---|---|---|---|
| 10 kgf | 0.45 mm | 0.46 mm | 0.455 mm | ~ 89.7 HV |
| 20 kgf | 0.50 mm | 0.51 mm | 0.505 mm | ~ 145.3 HV |
| 5 kgf | 0.30 mm | 0.31 mm | 0.305 mm | ~ 99.7 HV |
Values are rounded for demonstration only.
1) Purpose of Vickers hardness
Vickers hardness (HV) is a widely used measure of a material’s resistance to permanent surface deformation. Because the indenter is a diamond pyramid, the method works for very soft metals through hardened steels and many ceramics, allowing results to be compared across a broad range of strengths.
2) What the number represents
The reported value is proportional to the applied load divided by the indentation area. In practice, the calculator uses the standard constant 1.8544 with load in kgf and the mean diagonal in millimeters, producing HV in kgf/mm², which is convenient for lab reporting and specification sheets.
3) Typical load ranges and applications
Microhardness testing commonly uses 10 gf to 1 kgf for thin coatings, case depths, and small features. Conventional Vickers testing often spans 1 to 100 kgf for bulk metals. Select a load that gives a clean indentation without edge cracking or excessive pile-up.
4) Dwell time and surface preparation
Many standards use dwell times around 10–15 seconds to stabilize the impression before measurement. Proper polishing matters: a rough surface inflates diagonal readings and lowers HV. Keep the sample flat, clean, and well supported to avoid vibration or tilt errors.
5) Measuring diagonals correctly
Measure both diagonals (d1, d2) across the corners of the square impression. If they differ noticeably, check alignment, lighting, and focus. Averaging reduces random error, but large differences can indicate anisotropy, surface damage, or operator bias.
6) Unit handling and quick conversions
This calculator accepts load in kgf or newtons and diagonals in mm, µm, or inches. Internally, diagonals are converted to millimeters and force to kgf using 1 kgf = 9.80665 N. You can also view an approximate stress equivalent in MPa and GPa for context.
7) Reporting format and traceability
Professional reports often include the test load and dwell time with the result, for example: HV 10 / 15 s. Record the material condition (heat treatment, coating, location) and the instrument model. Consistent documentation makes results repeatable and easier to audit.
8) Common error sources and quality checks
The biggest contributors to uncertainty are diagonal measurement, surface finish, and incorrect load calibration. Take multiple indents and report an average with a spread. If results drift, inspect the indenter tip, verify the load, and repeat on a reference test block.
1) Can I calculate HV if I only measured one diagonal?
No. Vickers requires the mean of two diagonals. If only one is available, measure the second or repeat the indentation for a reliable hardness value.
2) What if my force is in newtons?
Select N as the load unit. The calculator converts N to kgf using 1 kgf = 9.80665 N, then applies the standard Vickers equation automatically.
3) Why are d1 and d2 different?
Small differences are normal from optics and surface texture. Large differences can come from tilted samples, poor polishing, uneven illumination, or material anisotropy. Recheck focus and repeat multiple indents.
4) Is HV the same as MPa?
HV is reported in kgf/mm². A common conversion is 1 kgf/mm² ≈ 9.80665 MPa. The MPa and GPa values shown here are approximate for quick comparison.
5) What load should I use?
Use a load that creates a clear indentation without cracking or excessive edge distortion. Microhardness work may use 10 gf–1 kgf, while bulk metals often use 1–100 kgf.
6) Can I compare Vickers to Rockwell?
They are different scales and indenters. Conversions exist but depend on material and hardness range. For specifications, prefer the scale required by the standard for your application.
7) Why export CSV or PDF?
Exports help document inputs, units, and results for lab notebooks, QA reports, and traceability. They reduce transcription mistakes and keep calculations consistent across repeat tests.
Accurate hardness values help engineers choose stronger materials confidently.