Vickers Hardness Test — ISO 6507 / ASTM E384

What Is Vickers?

The Vickers hardness test is a method in which hardness is calculated by pressing a square-based diamond pyramid with a 136° included angle into the specimen and measuring the two diagonals of the indentation. Because it leaves a small indentation, it can be used over a wide range of loads.

Purpose of Vickers

The purpose is to measure hardness in small areas such as thin sections, coatings, case-hardening depth and weld zones.

Which Products Is Vickers Applied To?

Thin sheet and strip
Coatings and surface-treated parts
Weld and heat-affected zone
Case-hardening depth measurement
Small precision parts

In Which Sectors Is Vickers Used?

MetalSteelMachineryIndustrial EquipmentPlastics

Standards Related to Vickers

ISO 6507-1
ASTM E384
ISO 4516

Vickers Conditions

Indenter: Square-based diamond pyramid with a 136° face angle
Load: A wide range according to application; HV1, HV5, HV10 and micro loads (HV0.1) are common
Dwell time: Defined in standard, typically 10–15 s
Surface: A polished surface suitable for diagonal measurement

Equipment for Vickers

Vickers hardness testing machine
Optical measurement system or automatic indentation recognition
Specimen preparation (cutting, mounting, polishing)
Reference blocks

Sample Requirements for Vickers

The surface must be prepared metallographically
Thickness is limited in the standard relative to indentation depth
A cross-section must be taken for case-hardening depth
The number of measurements is determined according to the application

Duration of Vickers

Duration per measurement is short. If specimen preparation (cutting, mounting, polishing) is required, the total can reach half a working day.

Vickers Procedure

1A specimen section is taken and polished metallographically.
2The machine is verified with reference blocks.
3The load appropriate to the application is selected.
4The indenter is pressed for the defined duration.
5The two diagonals of the indentation are measured and hardness is calculated.
6If case-hardening depth is required, measurements are taken in sequence from the surface inward.

Vickers Acceptance Criteria

The acceptance range is given in the product standard. If a hardness profile is required, the hardness value at a specified depth becomes the criterion.

Evaluation of Results

The indentation must be symmetric; asymmetric or distorted indentations are invalid. The hardness profile may also be presented graphically.

Vickers Report

Standard applied
Load and dwell time
Measurement locations and depths
Individual hardness values
Hardness-profile graph, if required

Accreditation

EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.

Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.

Scope and authorisations

Related Regulations

Heat-treatment and surface-treatment specifications
Welding-procedure-qualification requirements

Mekanik Testler — What Does This Testing Field Cover?

The section below describes the field that the Vickers test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.

Mechanical testing measures how a material or a part behaves under force. The family ranges from static loading (tension, compression, bending) to time-dependent behaviour (fatigue, creep), and from hardness and wear to fracture toughness.

What these tests have in common is that the result is reported as a MATERIAL PROPERTY. Yield strength or hardness is not a conformity decision; it is numerical data against which the design and the product standard will compare. Mechanical test reports are therefore usually an input to an engineering decision rather than to a product approval — material selection, safety factor, life prediction.

The distinction between static and dynamic behaviour is the key to understanding the field. A part may appear entirely unstressed under a static load yet break under repeated loading; fatigue fracture occurs at stresses well below the yield strength and gives no warning. For rotating, vibrating or cyclically loaded parts, a tensile test alone is therefore not sufficient evidence.

Test conditions determine the result, and this is critical for the readability of the report: specimen geometry, loading rate, temperature, conditioning and the gripping arrangement. The same material gives different values under different conditions. In plastics the rate effect is very pronounced, in metals the temperature effect; in composites the specimen orientation changes the result entirely.

Hardness is the most misused measurement in the field. Because it is fast, close to non-destructive and inexpensive, it is often used in place of strength. Conversion tables from hardness to strength exist, but they are APPROXIMATE and depend on the material group; using them as the sole evidence in material acceptance is wrong.

The fracture mechanics side requires a specific competence. Fracture toughness and fatigue crack growth rate measurements make it possible to calculate how long a cracked structure will last; they are the basis of damage-tolerant design in fields such as pressure equipment, aircraft structures and pipelines.

Method groups in this field

Static tests
Tension, compression, bending, shear and torsion. Yield and tensile strength, elongation and modulus of elasticity are obtained.
Impact tests
Charpy and Izod notch impact; the brittle-to-ductile transition behaviour of the material is determined as a function of temperature.
Hardness
Brinell, Vickers, Rockwell, Shore and micro hardness. Valuable for surface treatment depth and local differences in strength.
Fatigue
Force- and strain-controlled axial fatigue, fatigue in bending; S-N curves and the endurance limit.
Creep and stress relaxation
Behaviour under long-term load at high temperature; decisive for boiler, turbine and pressure equipment materials.
Fracture mechanics
Plane-strain fracture toughness, the J integral, CTOD and fatigue crack growth rate.
Wear and friction
Taber and rotating drum abrasion, coefficient of friction measurements.

Commonly confused in this field

Calculating strength from hardness is approximate; it cannot be used as the sole evidence in material acceptance.
Adequate static strength does not demonstrate fatigue strength; a cyclically loaded part requires a separate test.
If test rate and temperature are not reported, the result cannot be compared — especially for polymers and composites.
A test specimen and the actual part may not give the same value; moulding orientation, weld lines and differences in surface treatment all have an effect.
A strength value given for a composite without stating the specimen orientation is meaningless.
ASTM and ISO counterparts measure the same quantity but use different specimen geometries; the results are not treated as directly equivalent.

Which decisions these results support

Design verification and material selection
Incoming material control and supplier approval
Meeting the mechanical requirements of the product standard
Failure analysis, life prediction and damage tolerance calculation
Verifying heat treatment and surface treatment processes

Related Tests

Frequently Asked Questions About Vickers

Are Vickers and microhardness the same thing?

Microhardness refers to measurement with a Vickers or Knoop indenter at low loads (generally below 1 kgf). The method is the same; the load range differs.