For parts where centering is important (e.g., a boss on a plate).
Angles are notoriously difficult to maintain in welding due to distortion. en iso 13920-bf
In the context of EN ISO 13920, is not a tolerance class from the standard itself. Instead, it appears in welding symbols or technical notes to denote a specific weld preparation shape – typically Backing run with Flat face or Backing + Flat . For parts where centering is important (e
GENERAL TOLERANCES MACHINED PARTS: ISO 2768-mK WELDED CONSTRUCTIONS: EN ISO 13920-BF en iso 13920-bf
simplifies technical drawings by removing the need for hundreds of individual plus or minus
For more information on EN ISO 13920-BF, readers can refer to the following resources: