ISO 8970:2020,Timber structures — Testing of joints made with mechanical fasteners — Requirements for timber density.
A net friend shared this pdf file,which can be downloaded.The size of the file is 3.57M.
ISO 8970:2020 specifies a method based on density, for the selection of pieces of wood used in determining the strength and stiffness properties of joints between members of structural timber made with mechanical fasteners.
If the density distribution of the sample deviates from that of the timber to which the test results are applied, the observed resistances R shall be corrected as given in this annex.Background informationis given in Annex B.