According to DIN EN 1342, "paving stone" refers to a block of natural stone that is used as a paving surface and is produced by cutting or splitting.
Paving stones are defined in their dimensions as follows:
Nominal width ≤ 2 x thickness
Nominal length ≤ 2 x thickness
Nominal thickness ≥ 4 cm
Nominal dimensions denote the production dimensions. Actual dimensions, actual dimensions, may deviate from nominal dimensions within specified limits .
Thickness refers to the distance between the bottom and top of a paving stone.
Source: bauwion
