This part of JB/T 4366 specifies the type and size of the boring shaft end of floor-standing milling and boring machines. This section applies to boring spindles with boring spindle diameters of 130mm to 320mm for floor-standing milling and boring machines.
JB/T 4366.1-2011 Referenced Document
GB/T 3837-2001 7/24 tapers for tool shanks for manual changing