According to the EN ISO 13920 tables , the allowed deviation changes depending on how large the section is: : Allowed variation of Sizes over 30 mm up to 120 mm : Allowed variation of Sizes over 120 mm up to 400 mm : Allowed variation of Sizes over 400 mm up to 1000 mm : Allowed variation of Shape and Position (Class F)
It provides a uniform benchmark, ensuring that regardless of who fabricates the part, the outcome is consistent. en iso 13920-bf
Individual pieces prior to final assembly. Welded Structures: Structures containing welded joints. According to the EN ISO 13920 tables ,
If the final measurement shows length = 2,008 mm (violation by 3 mm), the part fails. The solution? Re-cut side members 5 mm short next time to compensate for weld shrinkage. If the final measurement shows length = 2,008
Geometrical rules ensure that components stay flat, straight, and properly aligned with interacting components. Class F parameters are determined based on the of the relevant surface or edge.