Disclaimer: This article is for informational purposes. Always refer to the latest official standards (ISO 286 / DIN ISO 286) for current engineering applications.
If the mating hole is (common hole tolerance), the assembly will have a defined, controlled clearance—ideal for a rotating shaft in an oiled bushing. Status: Superseded by ISO 286 It is crucial to note that DIN 71550 is no longer current . It was replaced by DIN ISO 286 (which corresponds to ISO 286), ensuring international alignment of fit standards. However, many workshops in Germany and across Europe still refer to “DIN 71550” colloquially, and older technical documentation frequently cites it directly. Din 71550
In the world of mechanical engineering and manufacturing, precision is paramount. When designing machine parts that must fit together—such as a shaft rotating inside a bearing or a piston moving within a cylinder—engineers cannot simply specify a single dimension (e.g., “20 mm”). Variations in manufacturing make exact replication impossible. This is where standardization bodies like DIN (Deutsches Institut für Normung) step in. Disclaimer: This article is for informational purposes