Key features and shortcomings of Stepping Motor

Stepper motors have numerous advantages:

They ensure univocal conversion of control impulses to displacement and can be employed in open-loop control applications;
Have a wide range of control frequencies;
They provide precision and high resolution for positioning;
Allow for sudden starting, stopping or reversing without losing steps;
Can hold their position;
Are highly compatible with numerical control.
But they also have disadvantages like:

Fixed step value (angular displacement) for a given motor;
Relatively low speed;
Low torque;
Low power efficiency.
The characteristics of a stepper motor such as linear stepping motor or closed loop stepping motor are strongly dependent to load and type of the actuation mechanism it is employed in, so that:

A certain resolution for the complete actuation system is imposed;
Loads, forces or inertia must be reduced at the motor’s shaft;
A certain speed characteristic must be defined for accomplishing movement;
The ratio between loads reflected to the motor’s shaft and the actual torque of the motor must be kept in adequate limits.