Creo Intelligent Fastener > Using Creo Intelligent Fastener > Appendix > Fastener Types > Nut Types > NUTTYPE 99
  
NUTTYPE 99
Use Nuttype 99 type if your nut type is not available. In the preview a rectangle appears for the nut head. Use E and K to define the maximum outline of your nut head. For this screw type, you must create an icon.
User-defined nuts