All masonry blocks are divided into stone compressive strength classes (SFK). This is derived from the stone compressive strength. The stone compressive strength indicates the maximum load that may be placed on the masonry blocks. The unit for this is N/mm². The higher the stone compressive strength class, the higher the static load capacity of the masonry blocks. In combination with the selected masonry mortar, the permissible compressive stress is derived from the SFK.
Common stone compressive strength classes are e.g. 12 and 20 for sand-lime brick walls.
Unit: no
Source: bauwion
