Magnetic Shielding Alloy Mu-Metal / HY-MU 80

Technical Data Sheet


Chemical Composition Limits
Weight% Ni Cu Cr S P Si Mn C Mo Fe
Hymu 80 (Comp1) 79.0-80.6     0.008 0.02 0.42 0.95 0.03 3.8-5 Rem
MIL N 14411C (Comp2) 75.0-77.0 4.0-6.0 3.0 0.02 0.02 0.50 1.8 0.05    

Mumetal is 80% nickel with additions of iron and molybdenum as main elements in turn this alloy offers an extremely high initial permeability. It is only moderately resistant to moisture and atmospheric corrosion, it used mainly in in transformer cores but is well known for its magnetic properties which are used for shielding electrical components from magnetic fields. "HYMU 80" has a minimum DC permeability of 80,000 at a flux density of 40 gauss when heat treated by the recommended procedure and test in accordance with ASTM 596

Typical Mechanical Properties


Yield Strength (psi) Tensile Strength (psi) Elongation in 2" (%)
44,000 100,000 40
Mechanical Properties in the Annealed Condition

Physical Properties (Annealed Condition)
Specific Gravity - 8.7g/cm
Curie Temperature - 830°F (410°C)
Electrical Resistivity, 349 ohm circ mil/foot 0.55 ohm mm
Density lb/ - 316
Thermal Conductivity - 134 btu-inch/ft hour °F 0.32 W/cm °C
Coefficient of Thermal Expansion, in./in. °F x 10 (-******)
°F x 10-6 between 70 and 400F
13cm/cm/ °C 10-6 between 30 and 204 °C

Mumetal is available in Sheet, Strip, Bar, Tubes and Rod. Contact Sales for further availability.

HYMU 80 
MAG 7904 
MIL N 14411 C, COMP. 1 
ASTM A753-78 and ASTM 596

At Aircraft Materials all stock items can be shipped out within 24 hours, usually within the same day. Even cutting orders for bar or sheet can be processed and dispatched the same day, and for time-critical situations such as AOGs, we have a dedicated AOG service desk ready to help (

Thanks to our global logistics network we can source from anywhere in the world in just a few days. We use a range of transport partners to enable us to ship overnight within the U.K. and Europe and provide fast shipping solutions to the rest of the world. If your requirement is urgent we can offer a priority shipping service, but also if time is not so critical we can offer more cost-effective options to ensure you get the best value for money. To find out more about our services click here.

Every effort is made to ensure that technical specifications are accurate. However, technical specifications included herein should be used as a guideline only. All specifications are subject to change without notice.

Sell your Stock Online at