XS_MAX_SPACE_BETWEEN_COMPLEX_ASSEMBLY_PARALLEL_PARTS
Category in Advanced options dialog: Dimensioning - parts
Use this advanced option to
define the maximum distance allowed between parallel parts for Tekla Structures to dimension them as one. The default value is 1000.
This advanced option is role specific. When the type SYSTEM(ROLE) is in use, the default value is used. When the type MODEL(ROLE) or DRAWING(ROLE) is in use, you can change the value, which is then the same for all users in the current model.