NF EN ISO 7094 Standard Dimensions for
Plain washers extra large series product grade C for wood constructions
This standard specifies the requirements for the washers, class C, with particularly large diameter. They are used especially for screws and nuts in the wooden buildings. R form with round hole for nominal thread diameter from 5 to 52 mm. V shape with square hole for nominal thread diameter from 5 to 22 mm.
Dimensional Drawing and Technical Diagrams