This chapter describes the procedures, characteristics, and applications for static hardness test methods. It addresses test methods that are state of the art, commonly used, or that may find increased use due to certain advantages. The methods addressed are Rockwell hardness testing (ISO 6508 and ASTM E 18), Vickers hardness testing (ISO 6507, ASTM E92, and ASTM E384), Brinell hardness testing (ISO 6506 and ASTM E10), and Knoop hardness testing (ISO 4545 and ASTM E284). The chapter also discusses the advantages and disadvantages of these test methods.

This chapter discusses the characteristics, advantages, and disadvantages of nondestructive hardness testing methods for metals, including electromagnetic impulse testing, photothermal testing, scratch hardness testing, and ultrasonic contact impedance testing. It also discusses the use of ultrasound to determine the depth of hardening in a metal or alloy. The chapter reviews methods used to check and calibrate hardness testing machines and indenters and the use of hardness reference blocks for verification and calibration of test machines. It also addresses conversion of hardness values determined by one method to equivalent values for a different method.

This chapter reviews the tests and procedures used for measuring hardness of plastics and elastomers. The conventional testing methods (Rockwell, Vickers, Brinell, and Knoop) used for testing of metals are based on the idea that hardness represents the resistance against permanent plastic deformation of the material to be tested. However, elastic deformation must be considered in hardness measurement of elastomers. This chapter discusses the equipment and processes involved in the durometer (Shore) test, the International Rubber Hardness Degree test, and other specialized tests. It presents the criteria that can be used to select a suitable hardness testing method for elastomers or plastics and describes processes involved in specimen preparation and equipment calibration.

This chapter discusses the history of hardness testing and defines the term hardness. It describes the interrelationship between material structure and hardness and the relationships between hardness and other mechanical material properties. In addition, information on the hardness unit and traceability of the hardness measurement are provided.

In dynamic hardness tests, the test force is applied to the defined indenter in an accelerated way (with a high application rate). Dynamic test methods relate hardness to the elastic response of a material, whereas the classical static indentation tests determine hardness in terms of plastic behavior. This chapter describes the most important and widespread dynamic hardness testing methods. These tests fall into two categories: methods in which the deformation is measured and methods in which the energy is measured. Methods that measure deformation include the Poldi hammer method, the shearing force method, the Baumann hammer method, and the Dynatest method. Methods that measure energy include the Shore method, the Leeb method, and the Nitronic method. The chapter concludes with a discussion of applications of dynamic hardness testing.

Instrumented indentation hardness testing significantly expands on the capabilities of traditional hardness testing. It employs high-resolution instrumentation to continuously control and monitor the loads and displacements of an indenter as it is driven into and withdrawn from a material. The scope of application comprises displacements even smaller than 200 nm (nano range) and forces even up to 30 kN . Mechanical properties are derived from the indentation load-displacement data obtained in simple tests. The chapter presents the elements of contact mechanics that are important for the application of the instrumented indentation test. The test method according to the international standard (ISO 14577) is discussed, and this information is supplemented by information about the testing technique and some example applications. The chapter concludes with a discussion on the extensions of the standard that are expected in the future (estimation of the measurement uncertainty and procedures for the determination of true stress-strain curves).

This chapter reviews the general principles involved in codifying standards and describes the historical development of materials testing standards. It provides information on the standards related to the Brinell, Vickers, Rockwell, and Knoop methods as well as those for the instrumented indentation test and hardness conversions.