This part of ISO 9270 specifies the dimensions and tolerances of 7/24 taper spindle noses with tenons for automatic tool changers, intended for use with the corresponding tool shanks of forms J, JD and JF according to ISO 7388-2.
GSO ISO 9270-2:2016 history
2016GSO ISO 9270-2:2016 7/24 taper spindle noses for automatic tool changers -- Part 2: Dimensions and designation of spindle noses of forms J and JF