Lifting a load that sits flat on the floor with no clearance beneath it. The projecting toe slides into a gap of a few millimetres and lifts from there, with the jack body alongside rather than underneath - which breaks the circular problem of needing to lift something before a jack will fit under it.

Because lifting on a projecting toe applies a bending moment to it that a straight downward load on the head does not. The two capacities are quoted separately for that reason, and treating the head rating as the toe rating is what bends toes and drops loads.

Working in stages: lift on the toe, pack the load with blocks, lower, reposition and lift again - often transferring to the jack's head once there is clearance. Repeating that cycle raises a machine progressively to skate or roller height without ever relying on the jack to support it.

Machinery moving and installation - machine bases, transformers, generator sets, presses and heavy cabinets that sit directly on a floor with no gap beneath them. They are standard equipment for millwrights and rigging crews for exactly that reason, and usually the first tool out of the van on an installation job.

Rarely, and it should not be attempted. Machines are normally lifted at several points using matched jacks, either sequentially with packing or together, so the load stays level and no single point is overloaded. Lifting one corner alone can twist a machine base or destabilise it.

Straight, unworn and undamaged. A bent or gouged toe has already been overloaded and its capacity is no longer what the label says. Toes should be inspected before each lift, and a visibly deformed one is a reason to take the jack out of service rather than to derate it.

Firm and level, like any jack, and with attention to the fact that the load is offset from the jack body. That offset makes stability more sensitive than with a bottle jack, so a spreader plate and a check that the toe is fully engaged before taking the weight both matter.