Is screw force the same as screw torque?

A lever works on the principle of using torque. A screw driver is used as a lever because the relatively broader handle produces much more torque for the same force as compared to the narrower blade of the screw driver.

moment of force (torque) i.e. the turning effect of a body(here,screw jack)= force applied X perpendicular distance of force from the axis of rotation. so in order to produce maximum turning effect of the screw jack by a force, the force is applied at a point on the body for which the distance from the axis is maximum so that the given force provides maximum torque to turn the screw jack. Thus,the screw jack is provided with a long arm.

A screwdriver allows you to exert more torque on a screw. Torque is defined as the product of the force exerted and the distance from the center of rotation. Torque is essentially a rotational force. It is simple to increase torque, simply increase the distance from the center that the force is being applied, and there is greater torque without increasing your effort. The handle is made to be wide, so that a greater torque can be exerted. It is also much easier to grip a screwdriver than it is to grip a screw. That also plays a factor.

Torque is the rotational effect of a force. It plays the same role in rotational motion as force plays in translational motion.

The turning effect of a force is called torque or moment of the force. SI unit of torque is Newton-Metre. T = FL i.e Torque = Force x Moment arm A couple is formed by two unlike parallel forces of the same magnitude but not along the same line.