Characteristics of the empirically developed Rockwell hardness test make it difficult to determine measurement uncertainty using methods based on mathematical models describing the relationship between the measurand and the influence quantities. An empirical approach to determining Rockwell hardness uncertainty has been developed, which provides a method based on the familiar procedures and practices of Rockwell hardness testing laboratories. The approach views the hardness machine and indenter as a single measuring device, and considers uncertainties associated with the machine repeatability and the usage of the machine over time with varying environmental conditions and with different operators. The approach also considers the measurement bias of the Rockwell hardness machine as compared to reference standards.

The paper describes the GALINDENT system that LTF – Galileo Hardness Testing Department, in co-operation with the Institute of Metrology "G. Colonnetti", has developed for the geometrical verification of Rockwell, Vickers diamond indenters, as prescribed by ISO Standards. This system consists of two instruments: an Interferometric Sine-Bar, for angular, straightness and flatness measures and a Rotary Table, for the verification of the spherical tip of Rockwell indenters. These two devices can be set up in one workstation, interfaced with the same computer for data analysis. A software package has been specifically developed to manage the entire system. The measurement test cycle is completely automated in order to ensure objective and reliable results. The operator interface, based on a graphic window menu in the Windows® environment, is extremely user friendly and it does not require any programming knowledge.

Part 3 of the ISO 14577 “Instrumented indentation test for hardness and materials parameters“ (IIT) concerns the calibration of reference blocks. Besides the widely spread activities for supplying reference blocks in the nano and micro range it is needed to be taken into account the macro range too. The paper reports on test results on ceramic materials which are tailored for reference blocks. The specimens made of Si3N4, SiC, or Al2O3 ceramics are highly homogenous and exhibit an increased quality with a roughness Ra ≤ 0.005 µm. They are successfully used for reference blocks of the traditional Vickers and Knoop hardness. In comparison, the capability of hardened steel which is used for traditional hardness techniques is studied.

In addition to the indirect verification using reference blocks and a reference indenter, it is possible to realise the calibration by direct verification of the test force, the indenter, the depth-measuring device and the testing cycle. Some conditions of the calibration process, e.g. the verification range, and the necessary accuracy of the depth-measuring device are described in standard ISO 6508-2. With reference to these parameters, a new depthmeasuring calibration device was developed. The study describes the function of this device and the calibration process. The advantages of this new process are that the measurement takes place in the axis of force application and that the calibration is independent of the Rockwell hardness scales. During calibration, the force stresses the calibration device but not the sensitive measuring sensor. Results of a real depth-measuring device verification are also presented.tion process. The advantages of this new process are that the measurement takes place in the axis of force application and that the calibration is independent of the Rockwell hardness scales. During calibration, the force stresses the calibration device but not the sensitive measuring sensor. Results of a real depth-measuring device verification are also presented.

Standardized mechanical test methods are referred in many materials and product standards for the characterization of quality of the materials or products. Mechanical testing is carried out on materials for three different reasons: - For quality control purposes to ensure that a material conforms to a technical specification or that it has been correctly processed. - To provide information which can be used in the design of a component or structure. - As part of investigations into the reasons for failures in service. Hence the results achieved from the mechanical testing of products that are made of / or from materials are used to help guarantee the safety and reliability of materials which in turn ensures the safety of those products. The paper gives an overview on the standardization activities of the last ten years for the different fields of mechanical testing as uniaxial, ductility, hardness, toughness and fatigue testing .