ISO40 and ISO50 are two specific types of interfaces specified by the DIN 2080 standard.
ISO40 refers to a tool shank with a 40-degree taper angle and a diameter ratio of 1:20. It is a common interface used in many machine tools, it is suitable for medium- to large-sized machine tools, and is compatible with a wide range of cutting tools, including milling cutters, drilling tools, and reamers.
ISO50 refers to a tool shank with a 50-degree taper angle and a diameter ratio of 1:25. It is a large and heavy-duty interface, and it is mainly used in high-performance and heavy-duty machine tools, such as those used for milling and boring operations, and for large cutting tools such as face mills and shell mills.
The DIN 2080 standard also specifies the dimensions, tolerances, and other technical requirements for these interfaces, which ensure that tool holders can be securely and accurately connected to machine tool spindles.