The block punch index test, requiring only a small cylindrical disc sa
mple, has been developed during the last decade and provides a practic
al index in assessing the strength of intact rock. In this study, earl
ier developments in the block punch index test are reviewed and a meth
od for sample size correction is described. Analysis of the results, o
btained from 23 different rocks, reveals that size correction in the b
lock punch index test is indispensable, A strong correlation was found
between the block punch index and the uniaxial compressive strength a
nd strength anisotropy. Utilization of the block punch index as an inp
ut parameter in rock mass classification was also suggested.