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LabCoda / Knowledge Base / Brinell Hardness

🔩 Brinell Hardness

Construction PN-EN ISO 6506-1

In short

Hardness measurement of metals by indentation of cemented carbide ball with specified force. The test is performed according to PN-EN ISO 6506-1:2014; Hardness range: ≤650 HBW (above — Vickers method). The procedure comprises 10 steps (about 24–34 min in total); it is used for: Quality control of structural and engineering steel, Testing of gray, spheroidal and malleable cast iron, Acceptance control of forgings and castings.

At a glance

  • Standard: PN-EN ISO 6506-1:2014
  • Category: Construction
  • Procedure steps: 10
  • Total time of stages: 24 min–34 min
  • Ball diameters: 1; 2.5; 5; 10 mm (cemented carbide HBW)
  • Test forces: 9.807 N to 29 420 N (1 kgf to 3000 kgf)
  • F/D² ratio: 1; 2.5; 5; 10; 15; 30 (standardized)

Overview

The Brinell method is one of the oldest and most widely used methods for measuring metal hardness, developed by Swedish engineer Johan August Brinell in 1900. It involves indenting a cemented carbide ball (designation HBW) of diameter D (1; 2.5; 5 or 10 mm) into the test material surface under a standardized force F, then measuring the diameter of the resulting indentation.

Brinell hardness is particularly useful for testing materials with coarse or non-uniform structure, such as cast irons, castings, forgings and low-alloy steels. The large ball leaves a relatively large indentation, which averages local hardness differences in the material (e.g., graphite in cast iron). The method is not suitable for very hard materials (>650 HBW) — then Vickers or Rockwell methods are used.

Standard PN-EN ISO 6506-1 specifies test conditions: the ratio of force to square of ball diameter (0.102 × F/D²) must correspond to one of the standardized values (1; 2.5; 5; 10; 15; 30). For steel, F/D² = 30 is standard (i.e., 10 mm ball, force 29.42 kN = 3000 kgf). Load application time is 10–15 s for steel.

Brinell hardness result is written in format: e.g., 200 HBW 10/3000/15, where 200 is hardness, 10 — ball diameter [mm], 3000 — force [kgf], 15 — application time [s].

Method principle

A cemented carbide ball (HBW) of diameter D is indented into the test material surface under force F for a specified time. Force is increased to final value in 2–8 s and maintained for 10–15 s (for steel). After unloading, indentation diameter d is measured in two perpendicular directions using a measuring microscope. Brinell hardness is calculated from formula: HBW = 0.102 × 2F / (πD(D - √(D² - d²))), or read from tables in standard PN-EN ISO 6506-4 based on measured indentation diameter.

Applications

Key parameters

ParameterValue
Ball diameters1; 2.5; 5; 10 mm (cemented carbide HBW)
Test forces9.807 N to 29 420 N (1 kgf to 3000 kgf)
F/D² ratio1; 2.5; 5; 10; 15; 30 (standardized)
Application time10–15 s (steel), 10–180 s (non-ferrous metals)
Hardness range≤650 HBW (above — Vickers method)
Measurement accuracy of d±0.5% of indentation diameter

Standard

Standard number
PN-EN ISO 6506-1:2014
Title (PL)
Metale — Pomiar twardości sposobem Brinella — Część 1: Metoda badań
Title (EN)
Metallic materials — Brinell hardness test — Part 1: Test method

Step-by-step procedure

  1. Specimen surface preparation

    Test surface must be smooth (Ra ≤ 1.6 µm), flat and free from oxides. Grind with P240–P600 paper if necessary. Degrease.

    ⏱ Time: 5–15 min

  2. Test parameter selection

    Select ball diameter D and force F based on material and specimen thickness. For steel: D = 10 mm, F = 29 420 N (F/D² = 30). Specimen thickness ≥ 8d.

    ⏱ Time: 2 min

  3. Hardness tester verification

    Perform measurement on certified reference block. Result must be within certificate uncertainty range. If not — calibration.

    ⏱ Time: 5 min

  4. Specimen placement

    Place specimen on hardness tester table. Ensure stable support (must not move or deform). Level.

    ⏱ Time: 2 min

  5. Indentation execution

    Apply preload. Increase to final force F in 2–8 s. Maintain for 10–15 s. Release load.

    ⏱ Time: 30 s

  6. Indentation diameter measurement

    Measure indentation diameter d in two perpendicular directions using microscope. Calculate average. Diameter must satisfy: 0.24D ≤ d ≤ 0.6D.

    ⏱ Time: 2 min

  7. Hardness calculation

    Calculate HBW from formula or read from tables in PN-EN ISO 6506-4. Record result in full form (e.g., 185 HBW 10/3000/15).

    ⏱ Time: 2 min

  8. Additional indentations

    Make minimum 3 indentations. Distance between indentation centers ≥ 3d, distance from edge ≥ 2.5d.

    ⏱ Time: 5 min

  9. Final result calculation

    Result = arithmetic mean of minimum 3 measurements. Assess scatter — if >5% from mean, investigate cause.

  10. Documentation

    Prepare report: material, dimensions, test conditions (D, F, t), individual indentation results, average, reference standard.

Required equipment and apparatus

EquipmentExampleIndicative price
Stationary Brinell hardness testerEMCO DuraVision G5, Wolpert/Wilson UH4000, Zwick/Roell ZHU30 000–120 000 PLN
Set of cemented carbide ballsHBW balls: Ø1, 2.5, 5, 10 mm — certified per ISO 6506-3200–800 PLN/set
Measuring microscope for indentationsIntegrated with hardness tester or external, magnification 20×–50×3 000–15 000 PLN
Hardness reference blocksCertified CRM per ISO 6506-3, e.g., 200 HBW, 400 HBW500–2 000 PLN/pc
Table and anvil for specimen mountingAdjustable, with V-blocks for cylindrical specimens1 000–5 000 PLN

Reagents, media and consumables

ReagentCASDetails
Hardness reference blocks—Certified reference materials CRM for hardness tester calibration, 2–3 ranges
Abrasive paper (surface preparation)—Grit P120–P600 for grinding specimen surface (Ra ≤ 1.6 µm)
Isopropyl alcohol67-63-0For degreasing specimen surface before testing

Health and safety (OHS)

Frequently asked questions

Which standard describes this test?

The test is performed according to PN-EN ISO 6506-1:2014 — “Metallic materials — Brinell hardness test — Part 1: Test method”.

How does this method work?

A cemented carbide ball (HBW) of diameter D is indented into the test material surface under force F for a specified time. Force is increased to final value in 2–8 s and maintained for 10–15 s (for steel).

What is the measuring range and accuracy?

Ball diameters: 1; 2.5; 5; 10 mm (cemented carbide HBW); Test forces: 9.807 N to 29 420 N (1 kgf to 3000 kgf); F/D² ratio: 1; 2.5; 5; 10; 15; 30 (standardized); Application time: 10–15 s (steel), 10–180 s (non-ferrous metals).

How long does the test take?

The times given for the individual stages add up to approximately 24 min–34 min. The procedure comprises 10 steps.

What equipment is required?

Stationary Brinell hardness tester, Set of cemented carbide balls, Measuring microscope for indentations, Hardness reference blocks, Table and anvil for specimen mounting. Indicative cost of the core instrument (Stationary Brinell hardness tester): 30 000–120 000 PLN.

Where is this test used?

Quality control of structural and engineering steel; Testing of gray, spheroidal and malleable cast iron; Acceptance control of forgings and castings; Testing of non-ferrous metals (aluminum, copper, bronze); Assessment of material condition after heat treatment; Correlation of hardness with tensile strength (Rm ≈ 3.5 × HBW); Failure analysis — assessment of material degradation.

What safety precautions apply?

Hardness tester — finger crushing risk when lowering indenter, do not hold specimen by hand; Heavy metal specimens — injury risk when handling; Metal filings during grinding — safety glasses mandatory; Isopropyl alcohol — flammable, use away from ignition sources.

Which laboratory can perform this test?

The test is performed by laboratories accredited to ISO/IEC 17025. On LabCoda you can find them by the standard number PN-EN ISO 6506-1.

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