All these years, I've save the plastic cylinders that oil furnace
nozzles come in, and I finally looked at what they say.

All start with .75 80^ (degrees) but there is a lot of variety in what
comes next. A,B, W, and the other brand's HA and Hx. (I can't find
it right now.)

I had in my mind that the proper nozzle was listed in the owner's
manual, but now that I'm looking, it seems not. (It says 0.75, but
nothing else) How do these technicians decide what nozzle to use,
just whatever the previous guy used? If so, how come there are so
many different containers left behind?

Thanks.