Depending on the application you might could fab some if you need to or if you have a blacksmith around you he can make some for you
You could make @ home Cherry red / orange bolt hammer form wing . A little harder to make the tapper from tread up to the wing Like shown in picture . Two pice die to form by hammer . or rod dowel bigger then thread needed. cut taper then the smaller thread cherry red / orange hammer wing shape
https://www.buckeyefasteners.com/sc...-thumb-screw-type-b-steel-zinc-bf 1024--6tsbz These are slightly different https://www.buckeyefasteners.com/sc...x-1-3-2-7-wing-screw-with-collar-st 2108--p44