What does the direction of torque signify

[vivinisaac]

what does the direction of torque signify (if a force is apllied to a wrench in the x-axis and the wrench lies on y-axis the nut also rotates in the xy pane but the direction of torque is in the z axis what does this direction show)

 

[Danger]

I'm sorry, but I don't quite understand the question.
The body that is supplying the torque rotates (or tries to) in the opposite direction. The body that is subjected to the torque rotates (or tries to) in the same direction.
Could you clarify your question a bit?

 

[rcgldr]

Rather than define torque as the plane it operates within, it's defined as a vector perpendicular to that plane. The standard is right hand rule; point your right hand thumb in the direction of the vector, and the direction your fingers move from open to closed fist is the direction of the torque force. Right hand rule also applies to angular velocity and angular acceleration. However, with the vector approach, there's no equivalent to angular "position". For this, you need to use the plane and an angular offset from some defined angular origin, normally the x axis, and the angle is counterclockwise displacement, as used in polar coordinates.

 

[Repetit]

The direction of the torque vector is always perpendicular to the plane of rotation. Therefore it has basically only two directions, up or down. This direction tells you whether the rotation caused by the force is clockwise or counterclockwise. There is nothing more to the direction of the torque vector.

 

[Loren Booda]

A possible definition:

Torque is the (cross) product between an angular force and its radius (torque arm), and oriented perpendicular to both.