Comparison of Five Methods Used to Measure Hardness (Classic Reprint)

How metals are tested for hardness—and why results differ by method.

This historical look at five hardness tests explains how scientists quantify a metal’s resistance to deformation. It covers well-known methods, their principles, and the practical steps used to carry them out. The text emphasizes how test setup, measurements, and interpretation shape the reported hardness values.

The book explains the Brinell method in detail, including the use of a hardened steel sphere, applied pressures, and how the indentation diameter relates to hardness. It also discusses how results depend on sphere size and load, and why the mean pressure or a calculated projection helps compare metals.
You’ll also learn about the cone test, a cone geometry variation, and how indentation depth and area calculations affect the hardness numeral. The influence of an indentation’s shape on results is explored, along with recommended corrections and limitations.
Other methods covered include the Shore scleroscope, which gauges hardness from hammer rebound; the Ballantine tester, which ties energy of impact to a measured indentation; and comparisons across these approaches to show where results agree or diverge.
What you’ll experience

• Explanations of key concepts like indentation depth, area, and load in different tests
• How readings are obtained, interpreted, and used for metal comparison
• Notes on practical limitations, instrument design, and data consistency
• A historical perspective on why multiple methods exist and how they relate

Ideal for readers of metallurgy, materials testing, or the history of engineering, who want a clear overview of how hardness is measured and compared across methods in practice.