[Rasper]

Sanding stainless by hand is a losing game. It's just too hard. You have to use a machine, unless you have a long, long time and a lot more energy than I have. I polish a lot of stainless, and I use a 3000 rpm machine with a soft pad. I usually start with 150, unless the metal is scratched badly, in which case I use 80 first. I go 150, 240 and 400. I use worn out 400 as a finish sanding, then go to emery on a stiff buff. I don't find it necessary to go higher than 400. Using the worn out 400 is enough.
Another thing. Stainless loves sandpaper; it eats it up. You might as well buy a lot of it. I have a little 3 inch air machine by Chicago Pneumatic and use 3M hook-it discs at 50 cents apiece. I can easily use up 50 dollars worth of discs in a day. Stainless is hard. It is hard to cut; it is hard to shape; it is hard to planish; and it is even harder to sand. The funny thing is: once I get it to the emery buff it polishes up fast. You need to bear down on it some, but it comes right up. Then I use green polish and then chrome rouge.
The important thing is, (and no one wants to hear this), you absolutely have to sand out all (and I mean ALL) of the scratches left by the previous grit sandpaper before you move on to the next. This takes a lot longer than you think, especially with stainless, a lot longer. But if you don't get them out, you will have to start all over again.
Get yourself a machine and a soft pad, if you have to rent it, borrow it, or sell your great mother's jewelry for it. You will save yourself a lot of grief.

Richard