Default Security Code For some Cellphone

Some time we need to 'Reset Default or Factory Reset or Master Reset' for our sets. For that we need Default security code. But if anybody change this code then this code does not work. But we know that most of them do not change there sets Default security code. Below some sets Default Security code.

Samsung: 0000 OR 000000 OR 00000000
Motorola: 0000 OR 000000 OR 00000000
Nokia: 12345
Techno: 0000
Siemens: 1234
Hyundai(Rankstel): 0000