I use 1" dowels for with the filament wall brackets I designed (they are published here) and don't want to waste any of the dowel so this let's me put them together using the pieces left after a cut.  The dowels I get from Menard's are snug, but will slip on without too much effort.  Your mileage may vary depending on the dowel.  The dowels from Menard's are 25.2mm diameter so 2 tenths of a millimeter under an inch.