Brinell vs Vickers

How to perform a hardness conversion between Brinell and Vickers?

Brinell and Vickers hardness numbers are derived from different principles and indenter geometries, but in many cases, a correlation between them is possible. Conversion is especially helpful when different specifications or industry standards call for results on different scales.

While direct mathematical formulas for converting Brinell to Vickers and vice versa are not universally applicable, empirical conversion tables based on test data are often used. These tables are published in ISO, ASTM and other technical standards and provide conversion guidance within specific hardness ranges and material types.

It’s worth noting that conversions may vary depending on the material being tested. For example, softer materials like aluminum may show more variation between the two methods than harder metals like steel. When precise mechanical properties are critical, it’s advisable to perform both tests independently rather than relying solely on conversions.

At UPI Laboratories Europe BV, we can help clients determine appropriate conversions for their specific materials and test conditions. However, it’s important to remember that conversions should be used carefully, especially when exact values are critical to product performance or safety.

Comparing Brinell and Vickers hardness tests: which method to choose?

Both Brinell and Vickers tests are static indentation methods, but they differ significantly in their application:

• Brinell: Uses Tungsten carbide ball, typically with larger loads (e.g., 500 to 3000 kgf). It creates a relatively large, round indentation and is ideal for coarse materials like castings and forgings.
• Vickers: Uses a diamond pyramid-shaped indenter with smaller, more precisely controlled loads. The method produces a square-shaped indentation and can be applied to all types of metals and small test areas.

In terms of accuracy, Vickers offers better precision due to its finer indentation and is commonly used in labs and research settings. Brinell is typically more suitable for field testing and quality control in production environments.

When to use Brinell vs Vickers hardness testing methods?

Choosing between Brinell and Vickers depends largely on your material, the accuracy required, and your operational setting. Here are some common scenarios:

• Use Brinell when testing heavy castings, forgings or when the material grain is too coarse for smaller indenters. It’s robust and better for structural materials.
• Use Vickers when testing small components, thin samples, coatings, or performing microhardness analysis. It’s highly versatile and allows for high-detail assessment.

Brinell tests tend to be more forgiving of surface imperfections and are ideal for larger samples or those that are difficult to section. Vickers, with its more delicate indentation, is sensitive to surface conditions and therefore requires more careful sample preparation.

The Brinell method is often preferred for rough or uneven surfaces, or where the structure of the material is too coarse for smaller impressions. On the other hand, Vickers is ideal for fine-structured materials, thin sections, and where detailed surface analysis is needed.

At UPI Laboratories Europe BV, we provide certified indenters and calibrated blocks for both Brinell and Vickers testing.

Need help choosing the right test method?

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