Replying to question on legs of rail...

hey, im puttin 2 in diamter legs on a 2-in diameter steel rail, i was wondering, since the weld probably wouldnt hold if i did it flat, should i cut a groove in the top of the legs for the rail to sit in? Would it be better to cut a V shape or a U shape? What is the best method of cutting a groove in it (ie. hacksaw, dremel, etc)? Im just wonderin how to make this rail the strogest i can so any help would be helpful...