Final answer:
The size of a tip for a size 15 D1 file would be specified by the manufacturer and would ordinarily be found in a tool-specific chart or guide.
Step-by-step explanation:
The question seems to pertain to the size of a tip for a D1 file. Typically, D1 might refer to a type of tool size specification, although without additional context it is not clear which industry or tool this is referring to. File sizes can be standardized based on the system being used, such as in engineering or metalwork, and the tip size may correlate with file size designation. If this is about a specific tool (such as a drill bit or file for metalworking), the corresponding tip size would usually be specified by the manufacturer, and you would need to consult a tool-specific chart or guide for this information.