En Iso 13920-bf [hot] -

is a specific technical designation used in engineering drawings to define general tolerances for welded constructions. It combines two distinct precision levels from the ISO 13920 standard to ensure that welded parts fit together correctly without needing individual, complex dimensioning for every single weld. Breaking Down the Code: "BF"

This refers to the tolerance for straightness, flatness, and parallelism. While linear dimensions use letters A through D, shape and position tolerances use E through H. Class F is the second-most precise level in this category (often considered "Medium" for shape). Why Use EN ISO 13920-BF? en iso 13920-bf

The suffix tells the manufacturer exactly which tolerance "bracket" to use for different types of measurements: is a specific technical designation used in engineering

This standard is widely used in machine construction , steel structures , rail vehicles, and shipbuilding. Tolerance Tables Overview While linear dimensions use letters A through D,