: Classes range from E (Fine), F (Medium), G (Coarse), to H (Very Coarse).
The designation refers to a specific set of general tolerances for welded constructions. It combines two distinct tolerance classes defined by the international standard ISO 13920 : Class B for linear and angular dimensions, and Class F for straightness, flatness, and parallelism. en iso 13920-bf
: Represents the tolerance class for linear and angular dimensions . "B" is generally considered a "medium" or "fine" grade for welding. : Classes range from E (Fine), F (Medium),