Drum brake or disc front? Twin-leading-shoe front or four?
On 2LS drum brake bikes, there's a thin washer that goes on the axle, at the shoulder where it presses against the brake backing plate. Another goes on the threaded end under the nut. Both #22 in this diagram:
Rear: same thing, both washers are #16:
Sometimes the one on the threaded end in the rear is thicker and chromed with a beveled edge.
4LS front brake:
None between the axle shoulder and the backing plate, just one the threaded end of the axle under the nut. (#19)