The hardness and elastic module of carbides and matrix of a high speed steel (HSS) roll material have been characterised by nanoindentation in the force range of 5-10 mN. It has been found that a different correlation needs to be applied to convert nanohardness to micro-Vickers hardness for the carbides and matrix. The pile-up phenomenon occurs significantly at the edge of the indent on the HSS matrix after nanoindentation, which resulted in a slight overestimation of the hardness. The nanohardness of the MC carbides, M2C/M7C3 carbides and HSS matrix is ,20·0, 12·6 and 9·2 GPa, which are in good agreement with the reported values by micro-Vickers test. © W. S. Maney & Son Ltd. 2013.