Hard and Soft Torque

Hard Torque:
Torque" is a way of describing how hard something is turned or twisted, in the same way we talk about "forces" as something that pushes or pulls. If we want to move a heavy box across the floor, we need a large force to push it. In the same way, if we want to turn a rusty bolt we will need a large torque.

Suppose you do have a rusty bolt that is stuck and you need to turn it. You know you will need a large torque to do this, but how can you make this? It's easy! It turns out that torque is the product of force and distance. In other words, to make a large torque you need either a large force or a large distance. To turn a rusty bolt you would put a wrench on it and push or pull on the end of the wrench. The "force" is how hard you push or pull, and the "distance" is how far from the bolt you are pushing or pulling. If you push or pull far away from the bolt, which requires a long wrench, the torque is bigger than if you push close to the bolt. If you have a really long wrench you dont need much force to turn your bolt, whereas if you only have a small wrench you will need to push or pull much harder to produce the same torque. Another important ingredient is that you push on the wrench in a direction perpendicular to the wrench.

Soft Torque:
An alternative name, used by some manufacturers, for snug torque.

I hope this will provide some clarity

Not sure if this is what your looking for ,but there is also a hard start torque and soft start. Hard start is just that, torque all at one time. Soft start is when the motor ramps up at a slower pace witch gives it the name soft start. I could go on more about it but, (this is an easy way of thinking of it.)

Thank you for your wonderful ellucidation, but I'd like to add something that the hard start torque is being provided by the DC motors, and the soft torque is being provided by the AC motor. The main difference between them is how to get the proper controlling of speed over the operation conditions. Regards,