Dewars are special vacuum-insulated containers designed to store liquid nitrogen at -196°C. They can be compared to industrial thermos flasks, used for cryogenic treatments on metal components.

One of its main uses is cryogenic shrink fitting, a highly effective and precise process for joining two mechanical parts (such as motor shafts and gears) by exploiting the contraction of metal at low temperatures.

How it works:

• The Dewar is filled with liquid nitrogen.
• The metal object to be treated is immersed inside.
• When in contact with nitrogen, the metal contracts.
• This contraction facilitates the insertion of the component (e.g. the drive shaft into the gear) without forcing.
• Once it returns to room temperature, the component expands and locks perfectly into place, ensuring a precise and durable fit.

Benefits of treatment with Dewar:

• No need to press or force the pieces.
• More stable and long-lasting couplings.
• Safe, accurate and repeatable process.