Mumetal when compared to iron at low magnetic field strengths can be up to 3-4 times more effective for the same thickness. However, at 3 times stronger fields then iron is 3-4 times more effective in shielding. Mumetal cost is high and availability is low. Mumetal is usually used where field strength is low, weight is a factor and the size is small. Since we wish to shield for strong magnetic fields then I recommend use of soft (annealed) iron instead of Mumetal. Our application does not warrant the cost of Mumetal.
Offered by Mike.