vickers hardness Testing Services: Precision Micro & Macro Hardness Evaluation for All Materials

As an independent third-party testing service provider, we offer comprehensive vickers hardness testing for a virtually unlimited range of materials – including metals, alloys, ceramics, composites, thin films, coatings, case‑hardened layers, and small or delicate components. The vickers hardness test, developed by Robert L. Smith and George E. Sandland at Vickers Ltd in 1921, is the most versatile indentation hardness method. It uses a diamond pyramid indenter (square‑based pyramid with a 136° included angle) and applies a single load from 1 gf (0.0098 N) to 120 kgf (1176 N). The resulting square indentation is measured optically, and the hardness value (HV) is calculated as the ratio of the test force to the indentation surface area. Because the indenter geometry remains constant regardless of load, the Vickers test yields a continuous, unitary hardness scale from very soft (≈ 20 HV) to extremely hard (≈ 2000 HV). Our accredited laboratory follows international standards (ISO 6507, ASTM E92, ASTM E384, GB/T 4340) to deliver accurate, reproducible, and legally defensible hardness data across micro, macro, and ultra‑micro scales. This article outlines our vickers hardness testing capabilities – including scope, key test items, load range selection, test procedures, and standard methods – to help manufacturers, heat treaters, quality control teams, and research laboratories obtain reliable hardness characterisation for any material.

1. What Is vickers hardness Testing?

The vickers hardness test is a static indentation method using a diamond pyramid indenter with a 136° included angle between opposite faces. The test force (F) is applied for a specified dwell time (typically 10‑15 seconds). After removal of the force, the two diagonals of the residual square impression (d₁ and d₂) are measured using an optical microscope or automatic measuring system. The arithmetic mean diagonal length d = (d₁ + d₂) / 2 is calculated. The vickers hardness (HV) is the quotient of the test force divided by the surface area of the indentation, calculated using the formula:

HV = 0.1891 × (F / d²) (for F in Newtons, d in millimetres) or HV = 1.8544 × (F / d²) (for F in kgf, d in millimetres).

The resulting HV number is dimensionless but is always reported with the test force value to indicate the load used. For example: 450 HV10 means a vickers hardness of 450 measured with a test force of 10 kgf (98.07 N). 800 HV0.1 indicates 800 HV measured with a test force of 0.1 kgf (0.9807 N) – used for thin layers or microhardness.

2. Our Testing Scope for vickers hardness

We cover all load ranges, material types, and specimen configurations:

By load range / application: Macro Vickers (5 kgf to 120 kgf) – for bulk materials, large components, and hardness mapping of structural parts; Micro Vickers (1 gf to 1000 gf / 1 kgf) – for thin sheets, small components, case‑hardened layers, carburised depth profiling, nitrided layers, electroplated coatings, and metallographic cross‑sections; Ultra‑micro / nano (by arrangement) – for thin films, MEMS devices, and advanced coatings.

By material type: Ferrous metals (carbon steel, alloy steel, stainless steel, tool steel, cast iron); Non‑ferrous metals (aluminium, copper, brass, bronze, titanium, nickel alloys, magnesium, zinc); Ceramics and hardmetals (alumina, zirconia, silicon carbide, tungsten carbide, cermets); Composites (metal matrix composites, ceramic matrix composites); Thin films & coatings (PVD, CVD, electroplated coatings – nickel, chromium, zinc; anodised layers); Case‑hardened layers (carburised, carbonitrided, nitrided, induction‑hardened, flame‑hardened); Welded joints (weld metal, heat‑affected zone – HAZ); Small components and delicate parts (gears, blades, bearings, miniature components).

By specimen configuration: Flat or curved surfaces; Bulk parts up to 1000 kg; Thin sheets (minimum thickness 0.1 mm for micro Vickers); Metallographic cross‑sections (mounted samples, 25 mm or 30 mm diameter); Small wires and pins; Coated samples (requires calibration of coating thickness).

By test environment: Laboratory (precision micro/macro testers); Elevated or low temperature (by arrangement); Ambient (23 ± 5°C standard).

3. International Standards & Compliance

All vickers hardness tests are performed in strict accordance with the following international standards:

ISO 6507‑1 (Metallic materials – vickers hardness test – Part 1: Test method) – defines the principle, symbols, test force range (0.09807 N to 1176 N / 0.01 kgf to 120 kgf), and calculation procedure for macro and micro Vickers.
ASTM E92 (Standard test methods for vickers hardness and knoop hardness of metallic materials) – covers macro Vickers testing (≥ 1 kgf).
ASTM E384 (Standard test method for microindentation hardness of materials) – covers micro Vickers (1 gf to 1000 gf) and includes detailed specimen preparation and indentation measurement guidelines.
GB/T 4340.1 (Metallic materials – vickers hardness test – Part 1: Test method) – Chinese national standard, aligned with ISO 6507‑1.
ISO 6507‑2 (Verification and calibration of testing machines) – specifies direct and indirect verification using certified reference hardness blocks.
ISO 6507‑3 (Calibration of reference blocks) – defines the calibration of reference hardness blocks for Vickers testing.
ASTM E140 (Hardness conversion tables) – provides conversion relationships between vickers hardness and other scales (HRC, HRB, HB, tensile strength).

4. Vickers Load Range Selection – Key Considerations

One of the greatest advantages of the Vickers test is the ability to select a test force appropriate for the specimen size, layer thickness, or expected indentation size. The following load ranges are commonly used:

Macro Vickers (≥ 5 kgf – 120 kgf) – For bulk materials, large components, and when the microstructure is coarse‑grained. Typical loads: 5 kgf, 10 kgf, 20 kgf, 30 kgf, 50 kgf, 100 kgf, 120 kgf. The resulting indentation diagonal ranges from approximately 0.2 mm to 1.5 mm depending on hardness and load. The specimen thickness must be at least 1.5 times the diagonal length (or > 1.0 mm for most macro loads).
Micro Vickers (1 gf to 1000 gf / 1 kgf) – For small parts, thin sections, case‑hardened layers, coatings, and metallographic mounted samples. Common loads: 1 gf (0.0098 N), 5 gf, 10 gf, 25 gf, 50 gf, 100 gf, 200 gf, 300 gf, 500 gf, 1000 gf. The indentation diagonal at micro loads ranges from 10 μm to 100 μm, requiring accurate optical measurement (typically 400× to 1000× magnification). The specimen or layer thickness must be ≥ 10× the indentation depth to avoid substrate influence.

General selection rule – For homogeneous materials, the measured vickers hardness should be independent of test load (load‑invariant). However, for case‑hardened or coated systems, a specific load may be selected to match the required depth of measurement (e.g., 50 gf for a 50 μm carburised layer). For bulk materials, macro loads (≥ 10 kgf) are preferred to minimise the effect of local inhomogeneities.

5. Test Procedure & Specifications

Our laboratory strictly follows the procedural requirements of ISO 6507‑1, ASTM E92/E384, and GB/T 4340.1. The key steps and specifications are summarised below:

Specimen preparation – For macro Vickers (≥ 5 kgf), the test surface must be flat, smooth, and free from oxide scale, grease, and coarse machining marks. A surface finish of Ra ≤ 0.4 μm is recommended, achieved by grinding with 600‑1200 grit paper and polishing with 1‑3 μm diamond paste. For micro Vickers (≤ 1 kgf), a mirror‑like finish (Ra ≤ 0.1 μm) is essential to enable precise measurement of indentations that are only 10‑50 μm in diagonal length. Metallographic mounting and polishing are standard for cross‑sectional microhardness traverses (e.g., case depth profiling). The specimen thickness must be at least 1.5 times the indentation diagonal length (or at least 10× the indentation depth, whichever is larger).

Indentation procedure – The test force is applied smoothly without shock or vibration. The force is maintained for a dwell time of 10‑15 seconds (standard); for soft materials (e.g., pure aluminium, lead), dwell times of 20‑30 seconds are used to allow full creep. After dwell, the force is removed, and the indentation is measured.

Measurement of indentations – The two diagonals (d₁ and d₂) are measured using an optical microscope equipped with a calibrated reticle or an automated image analysis system. For macro Vickers, magnification of 100× to 200× is typical; for micro Vickers, 400× to 1000× is required. The two diagonals are measured, and the arithmetic mean d = (d₁ + d₂) / 2 is calculated. If the difference between d₁ and d₂ exceeds 5% of the smaller diagonal, the indentation is considered irregular, and the test is repeated. For each valid indentation, the HV value is calculated using the standard formula.

Indentation spacing – The distance between the centre of an indentation and the specimen edge, or between adjacent indentation centres, must be at least 2.5 times the diagonal length for macro Vickers, and at least 3 times the diagonal length for micro Vickers to avoid edge effects and work‑hardening interference.

Number of indentations – For routine quality control, at least 3 indentations are made, and the average HV is reported. For acceptance testing or high precision, 5 indentations are standard. For microhardness traverse lines (e.g., case depth profiling), a series of indentations at defined intervals (e.g., every 0.05 mm or 0.1 mm) are made, and a hardness profile (HV vs. distance from surface) is generated.

Temperature – Tests are conducted at ambient temperature (23 ± 5°C). For high‑precision testing, 23 ± 1°C is maintained.

Verification of equipment – The vickers hardness tester is verified daily (or before each test series) using certified reference hardness blocks covering the relevant hardness range (e.g., 200 HV, 400 HV, 800 HV). At least 5 indentations are made on the block; the average HV must be within the certified tolerance (±3% to ±5% depending on the block). For micro Vickers (< 1 kgf), verification blocks with low hardness variation are used. Annual indirect verification by an accredited calibration laboratory is performed per ISO 6507‑2, which includes direct verification of test force, measuring system, and indenter geometry.

6. Typical Applications & Materials

The vickers hardness test is extremely versatile and is used across many industries. Typical applications include:

Case‑hardened depth measurement (carburising, nitriding, induction hardening) – Micro vickers hardness traverses are conducted from the surface inward at defined intervals (e.g., 0.05 mm, 0.10 mm, 0.15 mm). The effective case depth is defined as the distance from the surface to where the hardness drops to a specified value (e.g., 550 HV for carburised steel). Standards: ISO 2639, GB/T 9450, QC/T 262.
Heat‑treated parts (quenching, tempering, annealing) – vickers hardness (macro, 10‑30 kgf) is used to verify the effectiveness of heat treatment. For tool steels, 600‑900 HV10 is typical; for spring steels, 400‑550 HV10; for annealed steels, 150‑250 HV10.
Coatings and plated layers – Micro Vickers (≤ 100 gf) is used to measure the hardness of electroplated nickel (≈ 500‑700 HV0.05), hard chromium (≈ 800‑1000 HV0.1), anodised coatings (≈ 300‑500 HV0.025), and PVD/CVD coatings (e.g., TiN, TiAlN: 2000‑3000 HV0.02). The indentation depth should be ≤ 1/10 of the coating thickness to avoid substrate influence.
Hardmetals and ceramics – Tungsten carbide (WC‑Co) and silicon carbide are routinely tested using macro Vickers (10‑30 kgf) to evaluate quality and wear resistance. Typical values: 1200‑1600 HV10 for WC‑Co; 2000‑2500 HV10 for Al₂O₃; 2500‑3500 HV10 for SiC.
Small or delicate components – Micro Vickers (50‑200 gf) is ideal for testing watch parts, medical implants, gear teeth, turbine blades, and miniature gears without damaging the component.
Welded joints – Micro vickers hardness mapping across the weld metal, heat‑affected zone (HAZ), and base metal is performed to detect softening or hardening issues.
Powder metallurgy parts – Vickers testing on sintered parts, with appropriate load selection to avoid porosity interference (macro loads of 10‑30 kgf are typical).
Research & failure analysis – Vickers microhardness is used to characterise phases, intermetallics, and individual microstructural constituents (e.g., martensite, bainite, ferrite).

7. Advantages & Limitations of vickers hardness Testing

Understanding the strengths and limitations of the Vickers method ensures proper application and interpretation.

Advantages: The Vickers test is a single, continuous hardness scale from very soft (≈ 20 HV) to extremely hard (≈ 2000 HV) – no scale switching is required. The diamond indenter is virtually non‑deformable, even for the hardest materials. The square pyramid geometry produces geometrically similar indentations regardless of load, meaning that hardness values are load‑independent for homogeneous materials – a major advantage over Rockwell and Brinell. The small indentation size (from < 10 μm to > 1 mm) allows testing of small parts, thin layers, or individual phases. The method is suitable for both macro and micro applications, making it the most versatile hardness test. Excellent for case depth profiling and thin coating evaluation. Good correlation with tensile strength for steels (similar to Brinell).

Limitations: The test is slower than Rockwell because the indentation must be measured optically, requiring an operator (or automated imaging system) and careful surface preparation – especially for micro Vickers. The specimen surface must be highly polished for micro Vickers to obtain sharp indentation corners; otherwise, measurement errors increase. The equipment is more expensive than Rockwell testers, especially automated micro Vickers systems with integrated imaging. Operator skill influences measurement accuracy (e.g., diagonal determination, focusing). For macro Vickers, the indentation may be too large for small finished components (but macro Vickers is still less damaging than Brinell).

8. Calibration & Verification of vickers hardness Testers

To ensure measurement accuracy and traceability, vickers hardness testers are verified by two complementary methods as specified in ISO 6507‑2 and ASTM E92/E384:

Indirect verification (routine operational check) – Performed using certified reference hardness blocks (calibrated according to ISO 6507‑3). For macro Vickers, at least 5 indentations are made on a block with hardness in the expected range. The average HV must be within the certified tolerance (typically ±3% of the block value). For micro Vickers, the tolerance may be ±5% due to smaller indentation sizes. Repeatability (the range of the 5 readings) must be ≤ 5% for macro and ≤ 8% for micro.

Direct verification (periodic machine calibration) – Performed by an accredited calibration laboratory (typically every 12 months) to verify: test force accuracy (±1.0% for macro, ±1.5% for micro), indenter geometry (pyramid angle 136° ± 0.07°), dwell timer (±0.5 s), and measurement system (microscope scale calibration, objective magnification accuracy).

Daily / weekly operational checks – For ISO/IEC 17025 compliance, an internal check using one or two reference blocks (covering the load range and hardness level to be used) is performed each day that tests are conducted. At least 3‑5 indentations are made, and results are recorded on control charts.

9. Reporting & Result Presentation

Our test reports are detailed, transparent, and compliant with ISO/IEC 17025 requirements. Each report includes:

Specimen identification – Material grade, heat number, component description, sampling location, orientation, and any special preparation (mounting, polishing).
Test conditions – Standard referenced (ISO 6507‑1, ASTM E92/E384, GB/T 4340.1), test force (e.g., 10 kgf, 0.2 kgf), dwell time, indenter type (diamond pyramid), temperature, and humidity.
Individual indentation data – For each indentation: measured diagonal lengths d₁ and d₂ (μm or mm), calculated HV value. For microhardness traverses, a table or graph of HV vs. distance from the surface is provided.
Statistical summary – Mean HV, standard deviation, range, and coefficient of variation. Minimum and maximum values.
Equipment calibration status – Model and serial number of Vickers tester, date of last calibration, reference block identification and certified values, verification results (comparison with block, repeatability).
Compliance statement – Pass/fail determination against specification limits, customer purchase order, or material standard (e.g., “The measured average hardness of 680 HV10 meets the requirement of 650‑750 HV10 for this material”). For case depth profiling, the effective case depth (mm) is reported according to the defined threshold (e.g., 550 HV).

10. Why Choose Our Third‑Party vickers hardness Testing Services?

As an independent laboratory, we provide unbiased, accurate, and legally defensible hardness data. Our strengths include:

ISO/IEC 17025 accreditation – Our vickers hardness testing laboratory holds CNAS and CMA accreditation, with regular participation in proficiency testing (e.g., ISO 6507 round robins).
Comprehensive Vickers testers – We maintain a fleet of macro Vickers testers (5‑120 kgf) and fully automated micro Vickers systems (1 gf to 1000 gf) with integrated optical measurement and image analysis. Our micro Vickers testers include motorised XY stages for automated case depth profiling and traverse lines, with measurement accuracy of ±0.5 μm.
Wide specimen accommodation – We can test small components (minimum thickness 0.1 mm), metallographic mounts (25 mm or 30 mm diameter), and large parts up to 1000 kg and 1.5 metres dimensions.
Fast turnaround – Routine Vickers testing (batch of 5‑10 specimens, 3‑5 indentations each) typically completed within 2‑3 business days. microhardness traverses (case depth profiling) within 3‑5 business days depending on number of points.
Complete supplementary testing – We can convert vickers hardness to Rockwell (HRC, HRB), Brinell (HBW), and approximate tensile strength (for steels) per ASTM E140. We also offer metallographic preparation (mounting, polishing) and microstructural analysis.
Confidentiality – Full protection of your component design, material composition, and quality records.
Consultative support – Our metallurgists assist with load selection, indentation spacing planning for hardness mapping, interpretation of load‑invariant behaviour (or deviations), and root cause analysis of hardness variations (e.g., decarburisation, residual stress, microstructural inhomogeneity).

Whether you need to measure the case depth of a carburised gear, evaluate the hardness of a thin ceramic coating, validate the heat treatment of a precision component, or perform phase‑specific microhardness characterisation for failure analysis, our vickers hardness testing experts are ready to deliver reliable, actionable results.

Get Started with Your vickers hardness Testing Project

Contact our team with your material type, required load or hardness range, component dimensions, applicable standard (ISO 6507, ASTM E92/E384, GB/T 4340), and any special requirements (microhardness traverse, case depth, coating-only hardness, welded joint mapping). We will provide a detailed quotation, sample submission guidelines (including surface preparation recommendations and minimum specimen thickness), and a testing schedule. Let us help you obtain precise hardness characterisation for any material, from macro bulk components to micro‑scale coatings and layers.

This article provides an overview of our vickers hardness testing capabilities. For specific test methods, sample quantity, and pricing, please request a tailored service proposal.