Class F defines the allowable variation for the shape and position of the structure. Common tolerances for Class F include: +1 mm. Over 120 to 400 mm: +1.5 mm. Over 400 to 1,000 mm: +3 mm. 4. Why Use EN ISO 13920-BF?
Headline: Why your welds are great, but your assembly still doesn't fit.
Angular tolerances are defined by the width of the shorter leg of the angle. en iso 13920-bf
For in Class B, the tolerance is determined by the length of the shorter leg of the angle: Up to 400 mm: ± 45 minutes of a degree. Over 400 to 1,000 mm: ± 30 minutes. Over 1,000 mm: ± 20 minutes. 3. Geometric Tolerances for Class F
Note: For small parts, the tolerance is looser because relative distortion is higher. Class F defines the allowable variation for the
In the world of metal fabrication, EN ISO 13920-BF isn't just a string of characters—it's the set of rules that keeps heavy structures from being "crooked." If you're building something like a heavy-duty roll trailer desorber unit , this standard is your blueprint for precision. The Story of the "Perfectly Imperfect" Weld
Geometrical rules ensure that components stay flat, straight, and properly aligned with interacting components. Class F parameters are determined based on the of the relevant surface or edge. Over 400 to 1,000 mm: +3 mm
The main criterion for selecting a particular tolerance class is based on the functional requirements that must be met for the structure to perform as intended.
(ISO 13920 has no BF). It most likely means: "Weld edge preparation type BF according to ISO 9692-1, with general tolerances according to EN ISO 13920."