FWIW. On several occaisions I've had difficulty finding piece-part hardware at the local Home Depot (I live in Ridgecrest, CA, in the middle of the Mojave Desert with few store options). However, the much smaller local TruValue hardware store seemed to carry a much larger variety of individual piece parts - the latest search got me 3mm x .5 screws, whereas the smallest Home Depot had was 4mm. Same thing happened in a search for other unusual bolts, screws and fasteners.
