Kuru Grey

Finnish Kuru Grey is a dark grey, fine-grained granite, which has excellent technical properties. It creates an atmosphere of harmony in both modern and classic surroundings. Kuru Grey is also very popular stone for monuments.

Technical properties

Water absorption (%) mean value 0,16
Standard deviation (%) 0,02
Apparent Density (kg/m3) mean value 2670
density from … To …(kg/m3) 2690 to 2710
Standard deviation(kg/m3) 8
Open porosity (%) mean value 0,38
standard deviation (%) 0,04
Flexural strength (MPa) mean value 10,3
Standard deviation(MPa) 1,7
Min exp value(MPa) 8,9
Flexural strength after frost (MPa) mean value 9,6
Change in mean flexural strength after 48 cycles (%) 13,0
Standard deviation(MPa) 1,3
Min exp value(MPa) 8,1
Compression strength (MPa) mean value 187
Standard deviation(MPa) 23,2
Min exp value(MPa) 116
Compression strength after frost (MPa) mean value 175
Standard deviation(MPa) 21,6
Min exp value(MPa) 124
Water absorption by Capillarity C (g/m2s0,5) mean value 0,273
Standard deviation(g/m2s0,5) 0,032
Skid resistance – dry polished mean value 48,7
Skid resistance – wet polished mean value 15,3
Skid resistance – dry honed mean value 51,3
Skid resistance – wet honed mean value 32,5
Abrasion resistance (mm) mean value 17
Resistance at the anchoring system
Mean breaking Load(N) 2400
Min exp value (N) 1727
Standard deviation (N) 400
d1(mm) 10,1
bA(mm) 47,4
Resistance to Thermal shock
visual changes no
max Mass change (%) 0,03
max res. Freq. change (%) 8,5
Water absorption by Capillarity C (g/m2s0,5) no directions
parallel mean value
Standard deviation
Water vapour resistance factor μ dry 10000
Water vapour resistance factor μ wet 10000


  • Extensive building projects
  • External use
  • Internal use