The magnets in use today in MRI are in the 0.5 Tesla to 2.0 Tesla range, or 5,000 to 20,000 gauss. Magnetic fields above 2 Tesla have not been approved for use in medical imaging, though much more powerful magnets up to 60 tesla are used in research. Compared with the earth's 0.5 gauss magnetic field, you can see how incredibly powerful these magnets are. Numbers like that help provide an intellectual understanding of the magnetic strength, but everyday examples are also helpful. The MRI suite can be a very dangerous place if strict precautions are not observed.
Metal objects can become dangerous projectiles if they are taken into the scan room.
For example, paperclips, pens, keys, scissors, hemostats, stethoscopes and any other small objects can be pulled out of pockets and off the body without warning. Credit cards, bank cards, anything with magnetic encoding will be erased by most MRI systems. The magnetic force exerted on an object increases exponentially as it nears the magnet. Imagine standing 15 feet away from the magnet with a large pipe wrench in your hand. You might feel a slight pull.