How or where can I get a replacement washer for the stem connection of an outside tap? That is the threaded connection between the tap body and the wall bracket. I've bought packets of washers of all sorts but none seem to be the correct thickness or type. The tap ends up in the wrong position, even upside down.
You don't use washers here - you wrap loads of PTFE tape around the tap stem, add a bit of thread sealant if you can and eventually the tap will twist straight. Catches many people out, this one.