About Our Granite

Technical data of Our granite

1. Compression strength: average value from about 1200 kg/cm2 to 1300 kg/cm2.

2. Water penetration: 0.26% of the volume.

3. Wear and tear strength: 2.5 g/cm2.

4. Raw density: 2.59 g/m3.

Bulgarian granites are also highly-resistable to freezing, lye and also acids and alkali-resistable. Granite is resistable to the aggressive influences of our civilization. At request, immediately are provided the respective test results.

Granite requirements in accordance with O NORM B3108

A highly-resisting natural stone must be used. The stones must be wind-resisting according to O Norm B3123, Part 1, freezing-resistant according to O Norm B3123, Part 2, and resistant to lye according to O Norm B3123, Part 4. The stones shouldn't have cracks and precipitations reducing their strength.

Differences in colour and structure are only acceptable to a degree, which corresponds to the certain rock resource field. "Inclusions"(spots) and passages (veins) are acceptable only when the stones are to be used for facings and the coverings are not below the minimum values of the mechanical properties. The peculiarities of the stone splits should not be underestimated.

Processing of visible surfaces in accordance with O NORM B2213

1. Rough surface splitting: divided by splitting cotters, the surface isn't to be processed any more.

2. Shaping (cut or roughly shaped): if the stone can not be brought to the shape needed through splitting, the bigger bulges are to be processed by a tooler hammer or jumper.

3. Rough-sharpened: processed by a sharpened tooler.

The rough-sharpened surfaces at some spots can show the structure of the surface that has been made when splitting.

4. Middle-sharpened by a tooler: even and smooth processed by an iron edge.

5. Fine-sharpened by a tooler: just like the middle-sharpened one but with closer to each other storkes made by the jumper.

6. Rough-sharpened by a bush-hummer: processed by a bush-hammer with a teeth distance of 10 mm (even surfaced). Small moves of the bush-hammer are acceptable as well as unprocessed spots on the surface and bulged spots.

7. Middle-sharpened by a bush-hummer: processed by a hammer with a tooth width of 7 mm, the rest is just like the rough-sharpened.

8. Fine-sharpened by a bush-hummer: it is processed by a hammer with a tooth width of 3-4 mm. No visible bulges and hollows are allowed.

9.  Rough-grinded: surface with rough traces of grinding achieved by grinding tools up to a grain size of 60.

10. Finely-grinded: surface with fine traces of grinding achieved by a grinding tool up to a grain size of 220.

11. Polished: most finely grinded surface achieved by grinding tools, with no visible traces of grinding.