Walker Magnetics CER SERIES - Manual (Page 6)

6
O.S. Walker Inc., CER Lift Magnet
IMPORTANT FACTS FOR THE
OPERATION OF LIFT MAGNETS
LOAD CHARACTERISTICS OTHER THAN JUST WEIGHT
MUST BE CONSIDERED IN ORDER TO DETERMINE
THE LOAD THAT ANY MAGNET CAN LIFT.
This statement is true for all lifting magnets because they all operate using the same funda-
mental 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
obviously reduces the magnet’s lifting capacity. There are many important factors which limit
the flow of these lines of force.
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 mag-
netic force are able to flow. After 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 re-
quired to reach full lifting capacity. Below such thickness of load, the user must ac-
cept 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 be-
tween 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 air. Also, a rough surface finish on the load creates an air gap be-
tween the magnet and load. Any of these conditions will reduce the magnet’s
lifting capacity.