All 1 oz Krugerrand should weigh 33.931gm and contain 31.1gm of gold, which is 1.0 oz fine. The remaining metal is 2.826gm of copper, or otherwise know as 22ct gold.
The diameter can vary between 32.77mm and 32.61mm. The thickness has slightly varied over the years from between 2.972 mm and 2.87mm before 1976. Between 1976 and 1979 the tolerance was 2.972mm and 2.740mm. After 1979 the thickness became between 2.84mm and 2.74mm.
As discussed on the Proof page the bullion Krugerrands have a much coarser reed and it can be seen easily with the naked eye.