KEVOS® MAKEOS · Materials
Brinell Hardness Test Check (Hardness, Validity Rules, Specification)
What Brinell hardness does this indentation give, was the test valid for the specimen thickness, edge distance and spacing, and is the result within specification?
Evaluation of a Brinell test from two perpendicular indentation diameters: mean diameter, hardness, indentation ratio, force–diameter ratio and depth (as the Brinell hardness tool), the approximate tensile strength for steel, and the validity checks against your rules for indentation ratio, least specimen thickness as a multiple of indentation depth, least edge distance and least spacing as multiples of the indentation diameter, and the specification range.
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How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Test force | kgf | Test force in kilograms-force (3000 kgf with a 10 mm ball for steel). |
| Ball diameter | mm | Diameter of the ball. |
| Indentation diameter 1 | mm | Indentation diameter measured in one direction. |
| Indentation diameter 2 (perpendicular) | mm | Indentation diameter measured at right angles. |
| Specimen thickness | mm | Thickness of the specimen under the indentation. |
| Distance from indentation centre to the edge | mm | Distance from the indentation centre to the nearest edge. |
| Distance to the nearest other indentation centre | mm | Distance to the centre of the nearest other indentation. |
| Your rules and specification | ||
| Smallest d ÷ D | Smallest indentation ratio your test standard allows. | |
| Largest d ÷ D | Largest indentation ratio allowed. | |
| Least thickness ÷ depth | Least specimen thickness as a multiple of indentation depth (from your test standard). | |
| Least edge distance ÷ d | Least edge distance as a multiple of the indentation diameter (from your test standard). | |
| Least spacing ÷ d | Least centre spacing as a multiple of the indentation diameter (from your test standard). | |
| Specification minimum | HBW | Lowest hardness the specification allows. |
| Specification maximum | HBW | Highest hardness the specification allows. |
Method and formulas
- Mean d = (d₁ + d₂) ÷ 2; HB = 2F ÷ [π D (D − √(D² − d²))]; depth = [D − √(D² − d²)] ÷ 2 (as the Brinell hardness tool).
- Validity: d ÷ D within the limits; thickness ≥ k × depth; edge ≥ k × d; spacing ≥ k × d.
- Approximate tensile strength (steel) ≈ 3.45 HB MPa.
- Example: d = 4.01 mm gives 227.58 HBW (about 785.14 MPa); the test meets the validity rules.
Limitations
- Indentation diameters must be measured accurately; a 1% error gives about 2% in hardness.
- Tensile estimate is approximate and for steels only.
- Example values are illustrations. Replace them with values for your actual task.
Typical uses
- Check a Brinell result before reporting it
- Choose a load and ball for a thin part
- Screen castings or forgings for hardness
Who it is for
- Test laboratory technicians
- Quality inspectors
- Materials engineers
What you get
- Mean diameter, hardness and depth
- Validity checks
- Specification and tensile estimate
Interpreting the result
- If the indentation is too large or too small for the ball, change the force so that d ÷ D falls in range.
References
- Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 1406–1412. Topic reference; no source tables or recommended settings are reproduced.
- ISO 6506-1 Metallic materials — Brinell hardness test — Part 1: Test method
WORKOS tools are screening and decision-support utilities. Verify important financial, engineering, safety, legal or operational decisions using appropriate professional standards and your organisation’s approved data.
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