En Iso: 13920-bf !link!

This represents the "Medium" or "Mean" tolerance class. It is the most commonly used class in general engineering and steel construction. It provides a balance between functional accuracy and cost-effective fabrication.

It acts as a universal language for international contracts, ensuring a manufacturer in Europe and a client in the Middle East have the same expectations for accuracy. en iso 13920-bf

The actual permissible deviation (in millimeters or degrees) depends on the of the part. For example, a 1,000 mm beam in Class B will have a specific allowed variation, whereas a 10,000 mm beam will have a larger allowable margin. Type of Measurement Class for "BF" Key Focus Areas Linear Dimensions B (Medium) Length, width, and height of parts. Angular Dimensions B (Medium) Deviations in angles and slopes. Shape & Position F (Medium) Straightness, flatness, and parallelism . Testing and Verification This represents the "Medium" or "Mean" tolerance class

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" It acts as a universal language for international

Using this standard shorthand simplifies communication between designers and fabrication shops. Instead of calculating individual limits for every length and angle, a single note——applies a pre-defined set of rules based on the size of the component.