En Iso 13920-bf [2021] [2024]

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.

This standard is widely used in machine construction , steel structures , rail vehicles, and shipbuilding. Tolerance Tables Overview

Compliance with is verified using standard workshop tools such as steel straightedges , tape measures, and vernier callipers. It is important to note that this standard covers dimensional accuracy, not weld quality (like cracks or porosity), which is instead governed by ISO 5817. IS0 13920 - iTeh Standards en iso 13920-bf

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.

Specifying "Class B" avoids the high costs associated with the ultra-precise "Class A," while preventing the safety or assembly risks of the looser "Class C". This represents the "Medium" or "Mean" tolerance class

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

The suffix tells the manufacturer exactly which tolerance "bracket" to use for different types of measurements: This standard is widely used in machine construction

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?