Why is Stainless Steel Hip Flask will not open it? This is mainly because of your cup filling into hot water, air and water which are expanding, such as water temperature decreased over a period of time, but has been contracted, so that caused a pressure difference inside and outside the cup, so it will Screw not open. The key is to want to open the cup to overcome this pressure difference.

  Method One: You can put hot water in the glass bubble, so that the water temperature such as Stainless Steel Hip Flask, and the volume was expanded, it is easy to open
 
  Method two: You can cup in the refrigerator, poured out to look after the cover with hot water can be easily opened.
 
  Method three: sheet metal lids in the cup and gently pry between the crevice, the air inside is easily opened. If you do not want to happen later, we usually do not recommend the Stainless Steel Hip Flask holding the lid too tight.