1.0mm non-heat treated MuMetal® tension tear. The breakage occurred at approximately 6400N at 40% extension.As part of our long standing practice of continual investment, Magnetic Shields has an on site tensile tester which we use for both quality control purposes and research purposes. Using the tensile tester we can study the performance of magnetic shielding under forces of up to 25,000N upon request for customers who require shielding in certain specialist situations. We can also assure the integrity of welded components within these high force applications.



 1.0mm non-heat treated MuMetal® tension tear. The breakage occurred at approximately 6400N at 40% extension.




To demonstrate the differing properties of heat treated MuMetal® to non heat treated MuMetal® we have tested the breaking force of strips of 1.0mm MuMetal® pieces in both of these states. It is evident from the images to the right that the heat treated MuMetal® has a grain-like structure that becomes exaggerated during extreme stretching. This grain-like structure is what gives heat treated MuMetal® a high magnetic permeability to allow it to shield effectively.

Please see our articles on B(H) curves and Magnetic Shielding - How Does it Work? for more information about the theory behind magnetic shielding.


1.0mm heat treated MuMetal® tension tear. It is clear to see the changes to crystalline structure that heat treatment causes when compared to the above tension tear of non heat treated MuMetal®. This break occurred at around 5000N and 70% extension.