Two cranes with the same capacity can be very different. The duty class (FEM 1Am, 2m, 3m… or ISO M4, M5, M6…) describes how hard the crane works: how often it lifts, how heavy the loads usually are, and for how many hours.
- Light duty: workshops and maintenance halls with occasional lifts
- Medium duty: production with regular lifts during the shift
- Heavy duty: continuous production, steel and foundry work
Choosing a duty class that is too low shortens the life of the hoist; too high costs more than needed.