How is this screw standing like this?I is this due to magnetism or any other cause? What is the principle behind this??

Standing like what? There is no attachment given in the question.

@ aravinthan 
There are no attachment in the question , but i think you are asking about the standing nature of screw . 
if so, they YES , its a property of magnetism , 
if you could refer , then electromagnets work in a simmilar fashion , and in that case the screw lines are attaching each other and constitute a spring . 
This is due to the property of electromagnets . 

electromagnets do have low rentitivity and high corecivity , 
so, thay are exhibiting this type of behaviour . 
KINDLY ASK THE QUESTION WITH PROPER ATTACHMENT , SO, THAT WE CAN HELP U SUITABLY .. 

ALL THE BEST ..