This standard specifies clearance hole diameters for general purpose applications. These values result from bearings area calculations in connection with bolts and nut product standards.
DIN EN 20273:1992 history
1992DIN EN 20273:1992-02 Fasteners; clearance holes for bolts and screws (ISO 273:1979); german version EN 20273:1991
1992DIN EN 20273:1992 Fasteners; clearance holes for bolts and screws (ISO 273:1979); german version EN 20273:1991