In the OFF position, the rotating magnet group changes orientation so that most of the magnetic flux is redirected through the internal steel circuit rather than through the workpiece. This greatly reduces the magnetic attraction at the working surface and allows the lifter to be released from the load.
This switchable magnetic circuit provides strong holding force without requiring a continuous external power supply during lifting.
Permanent magnetic lifters are available in different sizes and lifting capacities to accommodate a wide range of steel handling requirements. The specifications below cover multiple product series, with rated lifting capacities for both flat and round workpieces.
In addition to lifting capacity, the tables provide maximum pull-off strength, overall dimensions, operating temperature, and net weight for each model. Maximum pull-off strength is a test parameter and should not be used in place of the rated lifting capacity when selecting a magnetic lifter.
Surface condition and air gaps are equally important. Rust, scale, coatings, surface roughness, curvature, or other irregularities can create a gap between the lifter and the workpiece. Even a relatively small air gap can reduce the magnetic force available for lifting.
The shape of the load also affects capacity. Flat steel provides a larger and more consistent contact area with the lifter poles, while round workpieces have a smaller effective contact area. For this reason, the rated lifting capacity for round loads is generally lower than that for flat loads, as shown in the specification tables above.
Load dimensions and weight distribution should also be considered when choosing a model. Long, flexible, or unevenly balanced workpieces may require a different lifting arrangement than a compact load of the same weight. The rated lifting capacity should therefore be considered together with the actual workpiece conditions and the operating requirements specified for the lifter.
If you are selecting magnetic lifters for a specific application, the workpiece material, weight, dimensions, thickness, surface condition, and whether the contact surface is flat or round are all useful for model selection.
SDM offers multiple permanent magnetic lifter series with different lifting capacities and dimensions. Contact us with your lifting requirements, and we can help identify a suitable model based on the available specifications.
