Some washing machines on the market have larger drums than others, but the majority of washing machines have a capacity between 6 to 10kg. When you overload your washing machine, the washer adds extra stress to the motor and the tub bearings and you could damage your appliance. Original source: http://www.washingmachinerepairservices.co.uk/blog/what-happens-if-you-overload-a-washing-machine/