Mounting Stiff Metal Fender with Strive Bolts
Bikes from certain times and places have used large (compared to today) unthreaded holes and draw bolts for fender attachment. Many old French bikes are like this. You've wound up with hardware for one.



You need the type of hardware used to connect the same struts to an M5 eyelet. They're sometime's called R-clips or -clamps. Here are the Velo Orange ones, probably around the cheapest out there.