Screw Shaft

The Line Symmetry Element Based On The Spiral Rotation Compound Symmetry Action. The Helical Axis Present In Crystallography, Denoted As Nm (where M Is An Integer Less Than N), Is Called An N-fold Nm Type Helical Axis. The Basic Action Of Spiral Rotation Corresponding To The Nm Spiral Axis Is Denoted As L (360 °/n) T, Where 360 °/n Is The Base Angle Of Rotation Around The N-fold Spiral Axis, And The Translation In T Is Taken As M/n Of The Basic Period Of The Spiral Axis Axis. For Example, The Basic Action Of The Spiral Rotation That Can Restore The Crystal Structure Corresponding To The 32 Spiral Axis Parallel To The Direction Is To Rotate 360 °/3=120 ° And Then Perform A 2/3 Translation.