In practical use elevators are highly stressed components and require regular careful inspection.
In practice, sets of elevators and a spare duplicate are required on-site for general operations.
To latch around a piece of pipework a set of elevators need a precise internal diameter, with an appropriately profiled shoulder to accommodate the lower profile of a tool joint.
The latch mechanism has to prevent opening under radial loads of up to hundreds of tons.
For some purposes (casing elevators, and loading pipe into and out of the derrick), the elevators also need to resist cross-axial loads of the weight of the pipe joints.