About the Yale TPM Permanent Lifting Magnet:
TPM permanent lifting magnets are ideal tools for easy, quick and economical transport
of heavy objects made from ferro-magnetic material. Typical operating areas are workshops and warehouses,
loading and unloading of machines as well as construction of jigs and fixtures.
Factors that reduce the magnetic clamping force:-
Air gap: High magnetic forces created by the TPM allow the magnet to clamp
components through the air gap, however, air gaps will reduce the magnetic
performance as they provide a barrier between the contact surfaces. Air gaps
occur in a number of different ways such as paint, dust and heavy mill scale.
Poorly machined surfaces also constitute an air gap. Please down rate the
magnet capacity in accordance with the adhesive force/air gap diagram below.
Material thickness: If the TPM is used to lift plates thinner than the recommended
minimum thickness, the clamping forces will be significantly reduced. Performance curves
can be identified in conjunction with the adhesive force/flat thickness diagram below:
Contact area: Full lifting capacity can only be achieved when the magnet has full contact area with
the component being lifted. If the contact surface has holes in or is uneven then the performance will be
affected accordingly. Always carry out a trial lift in these circumstances to establish correct lifting before
transporting the load.
Material type: Certain materials have different abilities to carry magnetism. For materials other than mild steel a reduction
factor must be applied in order to calculate the effective clamping force.
Ferrous alloy steels 0.8
High carbon steels 0.7
Cast iron 0.55
Examples of reduced WLL:
Mild steel 500g
Cast iron 500kg x 0.55 = 275kgs