A national scale is set up for each hardness scale representing the reference hardness values in each country. From metrological and international trade aspects agreement between the national scales is very important. Good agreement makes possible good industrial cooperation. Therefore comparison between national scales is necessary. Comparison between national hardness scales and hardness scales set up by the producers of the reference blocks is necessary as well. The Rockwell measurement method is the most widely used hardness measurement method throughout the world. The measurement is practical, relatively easy to carry out and the measurement result is quickly and simply indicated on the indicator. Among the different Rockwell scales, the C scale is very useful. It satisfies demands for accurate hardness measurement especially during hardening process of steel, which is often applied in industry. In this paper comparative measurements between the Rockwell C national scales of Slovenia as measured by Zavod za gradbeni?tvo Slovenije (ZAG) and USA as measured by the National Institute of Standards and Technology (NIST) and the scale set up by a producer of reference blocks, David L. Ellis Co., Inc., are presented.

The mechanical properties of thin films can be measured by a variety of different techniques, with nanoindentation being one of the most recent developments in this growing field. By using a depthsensing indentation method it is possible to obtain quantitative values for the hardness and modulus, and thus gain better insight into the response of a material to controlled deformation at such small scales. However, previous work has shown that the effects of pile-up, particularly in soft films deposited on hard substrates, can produce significant overestimation of the hardness and modulus due to an underestimation of the true contact area by common nanoindentation analysis procedures. By measuring the topography of the residual indent using Scanning Force Microscopy (SFM) and combining this information with the indentation data, it is possible to gain a fuller understanding of the indentation method and its effects on the material being tested. In addition, the true contact area can be directly measured from the SFM images and subsequently used to recalculate the hardness of the material more accurately. Moreover, the SFM allows the plastic volume of indentation to be measured, from which hardness can also be calculated in terms of plastic work. Experimental results are presented for two types of thin film deposited on hard substrates where SFM analysis of indentations at varying depths gives significant additional information concerning the true response of the system to instrumented indentation at a nanometric scale. Pile-up effects can be precisely monitored as a function of depth and correlated to hardness variations encountered across the coating/substrate interface.

Center for Measurement Standards (CMS) had established a thin-film indentation testing system based on Akashi MZT-522. The electronic balance was made use of calibrating the testing force and the internal depth sensor was calibrated by laser hologauge. Five other uncertainty was also evaluated in the paper. Finally, the uncertainty of the thin-film indentation testing system reached a total of 5.02 %.

The paper describes calibration method of portable Brinell hardness testers, which have been manufactured for many years and used popularly in China, especially used in testing hardness of ferrous metals. A series of experiment have been done concerning hardness levels for calibration, thickness of hardness blocks, supports of the blocks, diameters of ball indenters and touch-method between the block and the support. Based on result obtained from tests mentioned above, it is given that specifications of portable Brinell hardness testers including indication error of 7%, repeatability of 4%, etc. Besides that, this paper, also, provide an equation of Brinell values vs indentation diameters based on a table, which could be useful for application of the testers.

This bilateral comparison in HRC between National Metrology Institute of Japan, (NMIJ) and National Institute of Metrology (Thailand), (NIMT) was done in order to establish the hardness scales of NIMT and confirm their accuracy, which was designated by NIMT ( 0.45 HRC). The hardness blocks of 20 HRC, 30 HRC, 40 HRC and 60 HRC, which all have uniformity within 0.1 HRC according to EN ISO 6508-3, were used in this comparison. They were measured by NMIJ and NIMT with different conditions in order to indicate the performance of machines and hardness scales. Agreement of machine performance is within ± 0.13 HRC and agreement of hardness scales is within ± 0.24 HRC.