800-WMAGNET
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This statement is true for all lifting magnets because they all operate using the
same fundamental laws of physics. Magnetic power is often pictured as lines
of magnetic force flowing from north pole to south pole. Anything that limits
the flow of these magnetic lines of force reduces the magnet’s lifting capacity.
There are many important factors which limit the flow of these lines of force.
LOAD CHARACTERISTICS OTHER THAN JUST WEIGHT MUST BE CONSIDERED IN
ORDER TO DETERMINE THE LOAD THAT ANY MAGNET CAN LIFT.
1. LOAD THICKNESS
The greater the number of lines of magnetic force flowing from a magnet into the load, the greater
the effectiveness of the magnet. The thicker the load, the more lines of magnetic force are able to
flow. Beyond a certain thickness of load, no additional lines of force will flow because the magnet
has reached its full capacity.
• Thin material (load) means less iron available, and thus fewer lines of magnetic force flow
from the magnet into the load. Therefore, the lifting capacity of the magnet is reduced.
• In some cases the magnet will attract more than one thin plate of material when set on a stack
of thin plates. DO NOT LIFT more than one plate at a time since the lower plate may not be
held sufficiently.
• The lifting guidelines provide the user with what minimum thickness of load is required to
reach full lifting capacity. Below such thickness of load, the user must accept the reduced
lifting capacity of the magnet as shown in the guidelines.
2. SURFACE CONDITIONS
Magnetic lines of force do not flow easily through air. They need iron in order to flow freely;
therefore, anything that creates a space or an air gap between a magnet and the load limits the
flow of magnetic lines of force, and thus reduces the lifting capacity of a magnet.
• MAGNET’S LIFTING SURFACE CONDITION —
The lifting surfaces of a magnet must be
clean, smooth, flat and free of nicks and burrs to minimize the air gap between a magnet and
the load. This magnet has been designed with soft, low carbon steel lifting surfaces in order to
maximize the lifting capacity; therefore, special care must be taken to protect these surfaces.
Follow the Inspection Instructions in this manual. Attaching or welding other materials to the
lifting surfaces in order to reduce wear should not be done with this magnet because it will
reduce the lifting capacity.
• LOAD SURFACE CONDITION —
Paper, dirt, rags, rust, paint, and scale act the same as an
air gap. A rough surface finish on the load also creates an air gap between the magnet and
load. Any of these conditions will reduce the magnet’s lifting capacity.
IMPORTANT FACTS FOR THE OPERATION OF LIFT MAGNETS
