Iso 13920-bf ((link)) - En

: This refers to the tolerance class for shape and position (straightness, flatness, and parallelism) . Key Features of ISO 13920 ISO 13920 An Explained Guide to Welding General Tolerances

ISO 13920 tolerances apply to the weldment (no external clamping force). If you force a distorted frame onto a flat table before measuring, you are cheating the inspection. Release clamps and let the part relax. en iso 13920-bf

is more than just a drawing note—it is a language of compromise between perfect design and real-world welding. By understanding that "B" stands for Medium tolerances and "F" typically implies general fabrication , you can set realistic expectations for cost, quality, and delivery. : This refers to the tolerance class for