Assessment Error Sources in Rockwell Hardness Measurements

Published

June 1, 1999

Author(s)

Walter S. Liggett Jr, Samuel Low, David J. Pitchure, Jun-Feng Song

Abstract

In the use of hardness test blocks, the uncertainty due to block non-uniformity can be reduced if one is willing to make measurements at specified locations on the blocks. Statistical methods for achieving this reduction are explained in this paper. The test block uses considered include assessment of repeatability and reproducibility and comparison of testing machines and indenters. The methods are based on measurement at the vertices and centers of regular hexagons laid out on block surfaces. Measurements from such locations can be combined to give results that would not be influenced by block non-uniformity were the hardness to have constant gradient across individual hexagons. Although they do not eliminate the effects of block non-uniformity completely, the methods described reduce these effects and, in addition, allow them to be more easily treated in the analysis of the measurements.

Proceedings Title

Proceedings of the IMEKO XV World Congress

Conference Dates

June 13, 1999

Conference Location

Osaka, 1, JA

Pub Type

Conferences

Keywords

experimental design, indentation hardness, measurement uncertainty, statistical methods, trend elimination

Citation

Liggett Jr, W. , Low, S. , Pitchure, D. and Song, J. (1999), Assessment Error Sources in Rockwell Hardness Measurements, Proceedings of the IMEKO XV World Congress, Osaka, 1, JA (Accessed May 3, 2025)