472-12STD Harley JD Primary Chain Guard Studs & Nuts. 1912-1920 All Models.
These are the standard studs that use an inner nut to fasten them to the engine case. (see pictures) They fit cases from 1912 to 1920 that were not threaded.
Fits All 1912 - 1920 Singles & Twins
Chain Guard Stud 472-12
Inside Case Nut BO759 1/4" - 24 TPI
Outside Case Nut 472-15 5/64" - 32 TPI