EN ISO 13920-BF is a specific technical callout for general tolerances in welded constructions, where B represents the tolerance class for linear/angular dimensions and F represents the class for shape and position. 💡 🛠️ Decoding the "BF" Designation
EN ISO 13920-BF is a specific tolerance designation for welded constructions that combines two different accuracy levels for dimensions and geometry . en iso 13920-bf
"GENERAL TOLERANCES: EN ISO 13920 – B (MEDIUM). ALL OTHER DIMENSIONS ± 0.5 mm" EN ISO 13920-BF is a specific technical callout
A very specific topic!
EN ISO 13920-BF defines a specific set of "General Tolerances" for welded structures. It is intended to replace specific tolerance indications on technical drawings where high precision is not critical. The "BF" classification represents a Medium/Fine tolerance grade, making it the most commonly specified default for structural steel and general machinery welding where aesthetics and fit-up are important, but machining-level precision is not required. Class C: Fine tolerance
Revision Note: The original 1996 version (EN ISO 13920:1996) was revised by the updated ISO 13920:2023 standard. ISO 13920 An Explained Guide to Welding General Tolerances