Magnetic force calculator

The magnetic force calculator makes an estimate of the translational and twisting forces on cylindrical objects of various metals with their central axis at various angles to the external magnetic field.

To use the calculator (for iOS devices download the Zoho Sheets app):

1.Select the material from the drop down list

2. Enter the object’s length (cm) and diameter (cm) and the angle of its axis to the field.

3. Enter the value of magnetic field (T) and spatial gradient (T/m). For in bore calculations the spatial gradient should be set to 0.

The results show the magnetic force on the object and also the theoretical result of an ASTM 2052 deflection test (see MRI safety standards and guidance). The torque and associated twisting force on each end of the object are shown. This force acts on both ends.

Values of magnetic susceptibility are indicative only and are not constant for ferromagnetic materials. Actual values depend upon method of fabrication and treatment and may differ.

For more information see Essentials of MRI Safety chapters 2 & 9.

Not to be used to determine implant safety in MRI. Always follow the MR Conditions.